diff --git a/clang-tools-extra/clangd/DumpAST.cpp b/clang-tools-extra/clangd/DumpAST.cpp
--- a/clang-tools-extra/clangd/DumpAST.cpp
+++ b/clang-tools-extra/clangd/DumpAST.cpp
@@ -184,6 +184,7 @@
       TEMPLATE_KIND(DependentTemplate);
       TEMPLATE_KIND(SubstTemplateTemplateParm);
       TEMPLATE_KIND(SubstTemplateTemplateParmPack);
+      TEMPLATE_KIND(UsingTemplate);
 #undef TEMPLATE_KIND
     }
     llvm_unreachable("Unhandled NameKind enum");
diff --git a/clang-tools-extra/clangd/SemanticHighlighting.cpp b/clang-tools-extra/clangd/SemanticHighlighting.cpp
--- a/clang-tools-extra/clangd/SemanticHighlighting.cpp
+++ b/clang-tools-extra/clangd/SemanticHighlighting.cpp
@@ -762,6 +762,7 @@
     case TemplateName::QualifiedTemplate:
     case TemplateName::SubstTemplateTemplateParm:
     case TemplateName::SubstTemplateTemplateParmPack:
+    case TemplateName::UsingTemplate:
       // Names that could be resolved to a TemplateDecl are handled elsewhere.
       break;
     }
diff --git a/clang/include/clang/AST/PropertiesBase.td b/clang/include/clang/AST/PropertiesBase.td
--- a/clang/include/clang/AST/PropertiesBase.td
+++ b/clang/include/clang/AST/PropertiesBase.td
@@ -620,6 +620,16 @@
     return TemplateName(declaration);
   }]>;
 }
+
+let Class = PropertyTypeCase<TemplateName, "UsingTemplate"> in {
+  def : Property<"foundDecl", UsingShadowDeclRef> {
+    let Read = [{ node.getAsUsingDecl() }];
+  }
+  def : Creator<[{
+    return TemplateName(foundDecl);
+  }]>;
+}
+
 let Class = PropertyTypeCase<TemplateName, "OverloadedTemplate"> in {
   def : Property<"overloads", Array<NamedDeclRef>> {
     let Read = [{ node.getAsOverloadedTemplate()->decls() }];
diff --git a/clang/include/clang/AST/TemplateName.h b/clang/include/clang/AST/TemplateName.h
--- a/clang/include/clang/AST/TemplateName.h
+++ b/clang/include/clang/AST/TemplateName.h
@@ -39,6 +39,7 @@
 class TemplateArgument;
 class TemplateDecl;
 class TemplateTemplateParmDecl;
+class UsingShadowDecl;
 
 /// Implementation class used to describe either a set of overloaded
 /// template names or an already-substituted template template parameter pack.
@@ -190,7 +191,8 @@
 class TemplateName {
   using StorageType =
       llvm::PointerUnion<TemplateDecl *, UncommonTemplateNameStorage *,
-                         QualifiedTemplateName *, DependentTemplateName *>;
+                         QualifiedTemplateName *, DependentTemplateName *,
+                         UsingShadowDecl *>;
 
   StorageType Storage;
 
@@ -224,7 +226,11 @@
     /// A template template parameter pack that has been substituted for
     /// a template template argument pack, but has not yet been expanded into
     /// individual arguments.
-    SubstTemplateTemplateParmPack
+    SubstTemplateTemplateParmPack,
+
+    /// A template name that refers to a template declaration through a specific
+    /// using shadow declaration.
+    UsingTemplate,
   };
 
   TemplateName() = default;
@@ -235,6 +241,7 @@
   explicit TemplateName(SubstTemplateTemplateParmPackStorage *Storage);
   explicit TemplateName(QualifiedTemplateName *Qual);
   explicit TemplateName(DependentTemplateName *Dep);
+  explicit TemplateName(UsingShadowDecl *Using);
 
   /// Determine whether this template name is NULL.
   bool isNull() const;
@@ -287,6 +294,13 @@
   /// structure, if any.
   DependentTemplateName *getAsDependentTemplateName() const;
 
+  /// Retrieve the using shadow declaration through which the underlying
+  /// template declaration is introduced.
+  ///
+  /// The underlying template declaration is not stored in the template name, it
+  /// can be retrieved via the using shadow declaration.
+  UsingShadowDecl *getAsUsingDecl() const;
+
   TemplateName getUnderlying() const;
 
   /// Get the template name to substitute when this template name is used as a
diff --git a/clang/include/clang/AST/TextNodeDumper.h b/clang/include/clang/AST/TextNodeDumper.h
--- a/clang/include/clang/AST/TextNodeDumper.h
+++ b/clang/include/clang/AST/TextNodeDumper.h
@@ -317,6 +317,8 @@
   void VisitTagType(const TagType *T);
   void VisitTemplateTypeParmType(const TemplateTypeParmType *T);
   void VisitAutoType(const AutoType *T);
+  void VisitDeducedTemplateSpecializationType(
+      const DeducedTemplateSpecializationType *T);
   void VisitTemplateSpecializationType(const TemplateSpecializationType *T);
   void VisitInjectedClassNameType(const InjectedClassNameType *T);
   void VisitObjCInterfaceType(const ObjCInterfaceType *T);
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -6125,6 +6125,9 @@
     return DeclarationNameInfo(subst->getParameterPack()->getDeclName(),
                                NameLoc);
   }
+  case TemplateName::UsingTemplate: {
+    return DeclarationNameInfo(Name.getAsUsingDecl()->getDeclName(), NameLoc);
+  }
   }
 
   llvm_unreachable("bad template name kind!");
@@ -6133,6 +6136,7 @@
 TemplateName
 ASTContext::getCanonicalTemplateName(const TemplateName &Name) const {
   switch (Name.getKind()) {
+  case TemplateName::UsingTemplate:
   case TemplateName::QualifiedTemplate:
   case TemplateName::Template: {
     TemplateDecl *Template = Name.getAsTemplateDecl();
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -9190,6 +9190,16 @@
     return ToContext.getSubstTemplateTemplateParmPack(
         cast<TemplateTemplateParmDecl>(*ParamOrErr), *ArgPackOrErr);
   }
+  case TemplateName::UsingTemplate: {
+    // auto *UTN = From.getAsUsingTemplateName();
+    auto UsingOrError = Import(From.getAsUsingDecl());
+    if (!UsingOrError)
+      return UsingOrError.takeError();
+    auto ToTemplateOrErr = Import(From.getAsTemplateDecl());
+    if (!ToTemplateOrErr)
+      return ToTemplateOrErr.takeError();
+    return TemplateName(cast<TemplateDecl>(*ToTemplateOrErr));
+  }
   }
 
   llvm_unreachable("Invalid template name kind");
diff --git a/clang/lib/AST/ASTStructuralEquivalence.cpp b/clang/lib/AST/ASTStructuralEquivalence.cpp
--- a/clang/lib/AST/ASTStructuralEquivalence.cpp
+++ b/clang/lib/AST/ASTStructuralEquivalence.cpp
@@ -517,6 +517,7 @@
    case TemplateName::Template:
    case TemplateName::QualifiedTemplate:
    case TemplateName::SubstTemplateTemplateParm:
+   case TemplateName::UsingTemplate:
      // It is sufficient to check value of getAsTemplateDecl.
      break;
 
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -2207,6 +2207,7 @@
     TD = TN.getAsQualifiedTemplateName()->getTemplateDecl();
     goto HaveDecl;
 
+  case TemplateName::UsingTemplate:
   case TemplateName::Template:
     TD = TN.getAsTemplateDecl();
     goto HaveDecl;
@@ -2383,6 +2384,12 @@
       Out << "_SUBSTPACK_";
       break;
     }
+    case TemplateName::UsingTemplate: {
+      TemplateDecl *TD = TN.getAsTemplateDecl();
+      assert(TD && !isa<TemplateTemplateParmDecl>(TD));
+      mangleSourceNameWithAbiTags(TD);
+      break;
+    }
     }
 
     // Note: we don't pass in the template name here. We are mangling the
diff --git a/clang/lib/AST/ODRHash.cpp b/clang/lib/AST/ODRHash.cpp
--- a/clang/lib/AST/ODRHash.cpp
+++ b/clang/lib/AST/ODRHash.cpp
@@ -150,6 +150,7 @@
   case TemplateName::DependentTemplate:
   case TemplateName::SubstTemplateTemplateParm:
   case TemplateName::SubstTemplateTemplateParmPack:
+  case TemplateName::UsingTemplate:
     break;
   }
 }
diff --git a/clang/lib/AST/TemplateName.cpp b/clang/lib/AST/TemplateName.cpp
--- a/clang/lib/AST/TemplateName.cpp
+++ b/clang/lib/AST/TemplateName.cpp
@@ -13,6 +13,7 @@
 #include "clang/AST/TemplateName.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclBase.h"
+#include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/DependenceFlags.h"
 #include "clang/AST/NestedNameSpecifier.h"
@@ -76,6 +77,7 @@
     : Storage(Storage) {}
 TemplateName::TemplateName(QualifiedTemplateName *Qual) : Storage(Qual) {}
 TemplateName::TemplateName(DependentTemplateName *Dep) : Storage(Dep) {}
+TemplateName::TemplateName(UsingShadowDecl *Using) : Storage(Using) {}
 
 bool TemplateName::isNull() const { return Storage.isNull(); }
 
@@ -86,6 +88,8 @@
     return DependentTemplate;
   if (Storage.is<QualifiedTemplateName *>())
     return QualifiedTemplate;
+  if (Storage.is<UsingShadowDecl *>())
+    return UsingTemplate;
 
   UncommonTemplateNameStorage *uncommon
     = Storage.get<UncommonTemplateNameStorage*>();
@@ -108,6 +112,9 @@
   if (SubstTemplateTemplateParmStorage *sub = getAsSubstTemplateTemplateParm())
     return sub->getReplacement().getAsTemplateDecl();
 
+  if (auto *USD = Storage.dyn_cast<UsingShadowDecl *>())
+    return cast<TemplateDecl>(USD->getUnderlyingDecl());
+
   return nullptr;
 }
 
@@ -153,6 +160,10 @@
   return Storage.dyn_cast<DependentTemplateName *>();
 }
 
+UsingShadowDecl *TemplateName::getAsUsingDecl() const {
+  return Storage.dyn_cast<UsingShadowDecl *>();
+}
+
 TemplateName TemplateName::getNameToSubstitute() const {
   TemplateDecl *Decl = getAsTemplateDecl();
 
@@ -222,7 +233,10 @@
 
 void TemplateName::print(raw_ostream &OS, const PrintingPolicy &Policy,
                          Qualified Qual) const {
-  if (TemplateDecl *Template = Storage.dyn_cast<TemplateDecl *>())
+  TemplateDecl *Template = Storage.dyn_cast<TemplateDecl *>();
+  if (getKind() == TemplateName::UsingTemplate)
+    Template = getAsTemplateDecl();
+  if (Template) {
     if (Policy.CleanUglifiedParameters &&
         isa<TemplateTemplateParmDecl>(Template) && Template->getIdentifier())
       OS << Template->getIdentifier()->deuglifiedName();
@@ -232,7 +246,7 @@
       Template->printQualifiedName(OS, Policy);
     else
       OS << *Template;
-  else if (QualifiedTemplateName *QTN = getAsQualifiedTemplateName()) {
+  } else if (QualifiedTemplateName *QTN = getAsQualifiedTemplateName()) {
     if (Qual == Qualified::Fully &&
         getDependence() !=
             TemplateNameDependenceScope::DependentInstantiation) {
@@ -253,15 +267,16 @@
       OS << DTN->getIdentifier()->getName();
     else
       OS << "operator " << getOperatorSpelling(DTN->getOperator());
-  } else if (SubstTemplateTemplateParmStorage *subst
-               = getAsSubstTemplateTemplateParm()) {
+  } else if (SubstTemplateTemplateParmStorage *subst =
+                 getAsSubstTemplateTemplateParm()) {
     subst->getReplacement().print(OS, Policy, Qual);
-  } else if (SubstTemplateTemplateParmPackStorage *SubstPack
-                                        = getAsSubstTemplateTemplateParmPack())
+  } else if (SubstTemplateTemplateParmPackStorage *SubstPack =
+                 getAsSubstTemplateTemplateParmPack())
     OS << *SubstPack->getParameterPack();
   else if (AssumedTemplateStorage *Assumed = getAsAssumedTemplateName()) {
     Assumed->getDeclName().print(OS, Policy);
   } else {
+    assert(getKind() == TemplateName::OverloadedTemplate);
     OverloadedTemplateStorage *OTS = getAsOverloadedTemplate();
     (*OTS->begin())->printName(OS);
   }
diff --git a/clang/lib/AST/TextNodeDumper.cpp b/clang/lib/AST/TextNodeDumper.cpp
--- a/clang/lib/AST/TextNodeDumper.cpp
+++ b/clang/lib/AST/TextNodeDumper.cpp
@@ -900,12 +900,17 @@
 }
 
 void TextNodeDumper::VisitTemplateTemplateArgument(const TemplateArgument &TA) {
+  if (TA.getAsTemplate().getKind() == TemplateName::UsingTemplate)
+    OS << " using";
   OS << " template ";
   TA.getAsTemplate().dump(OS);
 }
 
 void TextNodeDumper::VisitTemplateExpansionTemplateArgument(
     const TemplateArgument &TA) {
+  if (TA.getAsTemplateOrTemplatePattern().getKind() ==
+      TemplateName::UsingTemplate)
+    OS << " using";
   OS << " template expansion ";
   TA.getAsTemplateOrTemplatePattern().dump(OS);
 }
@@ -1575,10 +1580,18 @@
   }
 }
 
+void TextNodeDumper::VisitDeducedTemplateSpecializationType(
+    const DeducedTemplateSpecializationType *T) {
+  if (T->getTemplateName().getKind() == TemplateName::UsingTemplate)
+    OS << " using";
+}
+
 void TextNodeDumper::VisitTemplateSpecializationType(
     const TemplateSpecializationType *T) {
   if (T->isTypeAlias())
     OS << " alias";
+  if (T->getTemplateName().getKind() == TemplateName::UsingTemplate)
+    OS << " using";
   OS << " ";
   T->getTemplateName().dump(OS);
 }
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3686,7 +3686,8 @@
          "Use DependentTemplateSpecializationType for dependent template-name");
   assert((T.getKind() == TemplateName::Template ||
           T.getKind() == TemplateName::SubstTemplateTemplateParm ||
-          T.getKind() == TemplateName::SubstTemplateTemplateParmPack) &&
+          T.getKind() == TemplateName::SubstTemplateTemplateParmPack ||
+          T.getKind() == TemplateName::UsingTemplate) &&
          "Unexpected template name for TemplateSpecializationType");
 
   auto *TemplateArgs = reinterpret_cast<TemplateArgument *>(this + 1);
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -503,9 +503,10 @@
     FoundUsingShadow = nullptr;
   } else if (AllowDeducedTemplate) {
     if (auto *TD = getAsTypeTemplateDecl(IIDecl)) {
-      // FIXME: TemplateName should include FoundUsingShadow sugar.
-      T = Context.getDeducedTemplateSpecializationType(TemplateName(TD),
-                                                       QualType(), false);
+      TemplateName Template =
+          FoundUsingShadow ? TemplateName(FoundUsingShadow) : TemplateName(TD);
+      T = Context.getDeducedTemplateSpecializationType(Template, QualType(),
+                                                       false);
       // Don't wrap in a further UsingType.
       FoundUsingShadow = nullptr;
     }
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -11023,6 +11023,8 @@
       TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName();
       bool TemplateMatches =
           Context.hasSameTemplateName(SpecifiedName, GuidedTemplate);
+      // FIXME: we should consider UsingTemplateName and QualifiedTemplateName,
+      // otherwise we will emit bogus diagnostics.
       if (SpecifiedName.getKind() == TemplateName::Template && TemplateMatches)
         AcceptableReturnType = true;
       else {
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -11,11 +11,13 @@
 #include "TreeTransform.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
 #include "clang/AST/DeclFriend.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/AST/TemplateName.h"
 #include "clang/AST/TypeVisitor.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/LangOptions.h"
@@ -283,8 +285,14 @@
 
     if (SS.isSet() && !SS.isInvalid()) {
       NestedNameSpecifier *Qualifier = SS.getScopeRep();
-      Template = Context.getQualifiedTemplateName(Qualifier,
-                                                  hasTemplateKeyword, TD);
+      // FIXME: store the using TemplateName in QualifiedTemplateName if
+      // the TD is referred via a using-declaration.
+      Template =
+          Context.getQualifiedTemplateName(Qualifier, hasTemplateKeyword, TD);
+    } else if (!R.isAmbiguous() && R.begin()->getKind() == Decl::UsingShadow) {
+      UsingShadowDecl *Using = cast<UsingShadowDecl>(*R.begin());
+      Template = TemplateName(Using);
+      assert(Using->getUnderlyingDecl() == TD);
     } else {
       Template = TemplateName(TD);
     }
diff --git a/clang/test/AST/ast-dump-using-template.cpp b/clang/test/AST/ast-dump-using-template.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/AST/ast-dump-using-template.cpp
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -std=c++17 -ast-dump %s | FileCheck -strict-whitespace %s
+
+// Tests to verify we construct correct using template names.
+// TemplateNames are not dumped, so the sugar here isn't obvious. However
+// the "using" on the TemplateSpecializationTypes shows that the
+// UsingTemplateName is present.
+namespace ns {
+template<typename T> class S {
+ public:
+   S(T);
+};
+}
+using ns::S;
+
+// TemplateName in TemplateSpecializationType.
+template<typename T>
+using A = S<T>;
+// CHECK:      TypeAliasDecl
+// CHECK-NEXT: `-TemplateSpecializationType {{.*}} 'S<T>' dependent using S
+
+// TemplateName in TemplateArgument.
+template <template <typename> class T> class X {};
+using B = X<S>;
+// CHECK:      TypeAliasDecl
+// CHECK-NEXT: `-TemplateSpecializationType {{.*}} 'X<ns::S>' sugar X
+// CHECK-NEXT:   |-TemplateArgument using template S
+// CHECK-NEXT:     `-RecordType {{.*}} 'X<ns::S>'
+// CHECK-NEXT:       `-ClassTemplateSpecialization {{.*}} 'X'
+
+// TemplateName in DeducedTemplateSpecializationType.
+S DeducedTemplateSpecializationT(123);
+using C = decltype(DeducedTemplateSpecializationT);
+// CHECK:      DecltypeType {{.*}}
+// CHECK-NEXT:  |-DeclRefExpr {{.*}}
+// CHECK-NEXT:  `-DeducedTemplateSpecializationType {{.*}} 'ns::S<int>' sugar using
diff --git a/clang/test/CXX/temp/temp.deduct.guide/p3.cpp b/clang/test/CXX/temp/temp.deduct.guide/p3.cpp
--- a/clang/test/CXX/temp/temp.deduct.guide/p3.cpp
+++ b/clang/test/CXX/temp/temp.deduct.guide/p3.cpp
@@ -55,6 +55,9 @@
   }
   using N::NamedNS1;
   NamedNS1(int) -> NamedNS1<int>; // expected-error {{deduction guide must be declared in the same scope as template}}
+  // FIXME: remove the following bogus diagnostic
+  // expected-error@-2{{deduction guide is not written as a specialization of template 'NamedNS1'}}
+
   using namespace N;
   NamedNS2(int) -> NamedNS2<int>; // expected-error {{deduction guide must be declared in the same scope as template}}
   struct ClassMemberA {
diff --git a/clang/test/SemaTemplate/qualified-id.cpp b/clang/test/SemaTemplate/qualified-id.cpp
--- a/clang/test/SemaTemplate/qualified-id.cpp
+++ b/clang/test/SemaTemplate/qualified-id.cpp
@@ -31,6 +31,17 @@
   };
 }
 
+namespace test3 {
+namespace ns {
+template<typename T> class S { S(T); }; // expected-note3{{candidate constructor}}
+}
+namespace ns2 {
+using ns::S;
+}
+// Verify we print the right name for the using template name.
+ns2::S<int> s; // expected-error{{no matching constructor for initialization of 'ns2::S<int>'}}
+}
+
 namespace PR6063 {
   template <typename T> void f(T, T);
   
diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -1442,6 +1442,7 @@
 bool CursorVisitor::VisitTemplateName(TemplateName Name, SourceLocation Loc) {
   switch (Name.getKind()) {
   case TemplateName::Template:
+  case TemplateName::UsingTemplate:
     return Visit(MakeCursorTemplateRef(Name.getAsTemplateDecl(), Loc, TU));
 
   case TemplateName::OverloadedTemplate:
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -890,6 +890,18 @@
              functionDecl(hasDescendant(usingDecl(hasName("bar")))));
 }
 
+TEST_P(ImportDecl, ImportUsingTemplate) {
+  MatchVerifier<Decl> Verifier;
+  testImport("namespace ns { template <typename T> struct S {}; }"
+             "template <template <typename> class T> class X {};"
+             "void declToImport() {"
+             "using ns::S;  X<S> xi; }",
+             Lang_CXX11, "", Lang_CXX11, Verifier,
+             functionDecl(
+                 hasDescendant(varDecl(hasTypeLoc(templateSpecializationTypeLoc(
+                     hasAnyTemplateArgumentLoc(templateArgumentLoc())))))));
+}
+
 TEST_P(ImportDecl, ImportUsingEnumDecl) {
   MatchVerifier<Decl> Verifier;
   testImport("namespace foo { enum bar { baz, toto, quux }; }"