diff --git a/clang-tools-extra/clangd/InlayHints.cpp b/clang-tools-extra/clangd/InlayHints.cpp
--- a/clang-tools-extra/clangd/InlayHints.cpp
+++ b/clang-tools-extra/clangd/InlayHints.cpp
@@ -366,6 +366,12 @@
   std::vector<InlayHint> Results;
   InlayHintVisitor Visitor(Results, AST);
   Visitor.TraverseAST(AST.getASTContext());
+
+  // De-duplicate hints. Duplicates can sometimes occur due to e.g. explicit
+  // template instantiations.
+  llvm::sort(Results);
+  Results.erase(std::unique(Results.begin(), Results.end()), Results.end());
+
   return Results;
 }
 
diff --git a/clang-tools-extra/clangd/Protocol.h b/clang-tools-extra/clangd/Protocol.h
--- a/clang-tools-extra/clangd/Protocol.h
+++ b/clang-tools-extra/clangd/Protocol.h
@@ -1548,6 +1548,8 @@
   std::string label;
 };
 llvm::json::Value toJSON(const InlayHint &);
+bool operator==(const InlayHint &, const InlayHint &);
+bool operator<(const InlayHint &, const InlayHint &);
 
 struct ReferenceContext {
   /// Include the declaration of the current symbol.
diff --git a/clang-tools-extra/clangd/Protocol.cpp b/clang-tools-extra/clangd/Protocol.cpp
--- a/clang-tools-extra/clangd/Protocol.cpp
+++ b/clang-tools-extra/clangd/Protocol.cpp
@@ -1326,6 +1326,14 @@
   return llvm::json::Object{
       {"range", H.range}, {"kind", H.kind}, {"label", H.label}};
 }
+bool operator==(const InlayHint &A, const InlayHint &B) {
+  return std::tie(A.kind, A.range, A.label) ==
+         std::tie(B.kind, B.range, B.label);
+}
+bool operator<(const InlayHint &A, const InlayHint &B) {
+  return std::tie(A.kind, A.range, A.label) <
+         std::tie(B.kind, B.range, B.label);
+}
 
 static const char *toString(OffsetEncoding OE) {
   switch (OE) {
diff --git a/clang-tools-extra/clangd/unittests/InlayHintTests.cpp b/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
--- a/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
+++ b/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
@@ -612,6 +612,18 @@
                   ExpectedHint{": A<float>", "var"});
 }
 
+TEST(TypeHints, Deduplication) {
+  assertTypeHints(R"cpp(
+    template <typename T>
+    void foo() {
+      auto $var[[var]] = 42;
+    }
+    template void foo<int>();
+    template void foo<float>();
+  )cpp",
+                  ExpectedHint{": int", "var"});
+}
+
 // FIXME: Low-hanging fruit where we could omit a type hint:
 //  - auto x = TypeName(...);
 //  - auto x = (TypeName) (...);
@@ -625,4 +637,4 @@
 
 } // namespace
 } // namespace clangd
-} // namespace clang
\ No newline at end of file
+} // namespace clang