diff --git a/llvm/include/llvm/MC/MCWinCOFFStreamer.h b/llvm/include/llvm/MC/MCWinCOFFStreamer.h
--- a/llvm/include/llvm/MC/MCWinCOFFStreamer.h
+++ b/llvm/include/llvm/MC/MCWinCOFFStreamer.h
@@ -58,6 +58,7 @@
                         unsigned ByteAlignment) override;
   void emitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                              unsigned ByteAlignment) override;
+  void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
   void emitZerofill(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
                     unsigned ByteAlignment, SMLoc Loc = SMLoc()) override;
   void emitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
diff --git a/llvm/lib/MC/MCParser/COFFMasmParser.cpp b/llvm/lib/MC/MCParser/COFFMasmParser.cpp
--- a/llvm/lib/MC/MCParser/COFFMasmParser.cpp
+++ b/llvm/lib/MC/MCParser/COFFMasmParser.cpp
@@ -53,6 +53,8 @@
   bool ParseDirectiveSegmentEnd(StringRef, SMLoc);
   bool ParseDirectiveIncludelib(StringRef, SMLoc);
 
+  bool ParseDirectiveAlias(StringRef, SMLoc);
+
   bool ParseSEHDirectiveAllocStack(StringRef, SMLoc);
   bool ParseSEHDirectiveEndProlog(StringRef, SMLoc);
 
@@ -124,7 +126,7 @@
     // purge
 
     // Miscellaneous directives
-    // alias
+    addDirectiveHandler<&COFFMasmParser::ParseDirectiveAlias>("alias");
     // assume
     // .fpo
     addDirectiveHandler<&COFFMasmParser::ParseDirectiveIncludelib>(
@@ -384,6 +386,26 @@
   return false;
 }
 
+bool COFFMasmParser::ParseDirectiveAlias(StringRef Directive, SMLoc Loc) {
+  std::string AliasName, ActualName;
+  if (getTok().isNot(AsmToken::Less) ||
+      getParser().parseAngleBracketString(AliasName))
+    return Error(getTok().getLoc(), "expected <aliasName>");
+  if (getParser().parseToken(AsmToken::Equal))
+    return addErrorSuffix(" in " + Directive + " directive");
+  if (getTok().isNot(AsmToken::Less) ||
+      getParser().parseAngleBracketString(ActualName))
+    return Error(getTok().getLoc(), "expected <actualName>");
+
+  MCSymbol *Alias = getContext().getOrCreateSymbol(AliasName);
+  MCSymbol *Actual = getContext().getOrCreateSymbol(ActualName);
+
+  Alias->setVariableValue(MCSymbolRefExpr::create(Actual, getContext()));
+  getStreamer().emitWeakReference(Alias, Actual);
+
+  return false;
+}
+
 bool COFFMasmParser::ParseSEHDirectiveAllocStack(StringRef Directive,
                                                  SMLoc Loc) {
   int64_t Size;
diff --git a/llvm/lib/MC/MCWinCOFFStreamer.cpp b/llvm/lib/MC/MCWinCOFFStreamer.cpp
--- a/llvm/lib/MC/MCWinCOFFStreamer.cpp
+++ b/llvm/lib/MC/MCWinCOFFStreamer.cpp
@@ -308,6 +308,18 @@
   PopSection();
 }
 
+void MCWinCOFFStreamer::emitWeakReference(MCSymbol *AliasS,
+                                          const MCSymbol *Symbol) {
+  auto *Alias = cast<MCSymbolCOFF>(AliasS);
+  Alias->setIsWeakExternal();
+
+  BeginCOFFSymbolDef(AliasS);
+  EmitCOFFSymbolStorageClass(
+      COFF::SymbolStorageClass::IMAGE_SYM_CLASS_WEAK_EXTERNAL);
+  EmitCOFFSymbolType(COFF::SymbolBaseType::IMAGE_SYM_TYPE_NULL);
+  EndCOFFSymbolDef();
+}
+
 void MCWinCOFFStreamer::emitZerofill(MCSection *Section, MCSymbol *Symbol,
                                      uint64_t Size, unsigned ByteAlignment,
                                      SMLoc Loc) {
diff --git a/llvm/test/tools/llvm-ml/alias.test b/llvm/test/tools/llvm-ml/alias.test
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-ml/alias.test
@@ -0,0 +1,44 @@
+; RUN: llvm-ml -filetype=obj %s | llvm-objdump --syms - | FileCheck %s
+
+.code
+
+t1 PROC
+  ret
+t1 ENDP
+; CHECK: [[T1_ADDRESS:0x[0-9a-fA-F]+]] t1
+
+t2 PROC
+  ret
+t2 ENDP
+; CHECK: [[T2_ADDRESS:0x[0-9a-fA-F]+]] t2
+
+alias <t3> = <t1>
+; CHECK: (scl 69){{.*}}t3
+; CHECK-NEXT: AUX indx [[T3_DEFAULT_INDEX:[0-9]+]] srch 3
+; CHECK: {{^\[}} [[T3_DEFAULT_INDEX]]{{\]}}
+; CHECK-SAME: [[T1_ADDRESS]]
+
+alias <t4> = <t2>
+; CHECK: (scl 69){{.*}}t4
+; CHECK-NEXT: AUX indx [[T4_DEFAULT_INDEX:[0-9]+]] srch 3
+; CHECK: {{^\[}} [[T4_DEFAULT_INDEX]]{{\]}}
+; CHECK-SAME: [[T2_ADDRESS]]
+
+alias <t5> = <foo>
+; CHECK: (scl 69){{.*}}t5
+; CHECK-NEXT: AUX indx [[T5_REFERENCE_INDEX:[0-9]+]] srch 3
+; CHECK: {{^\[}}[[T5_REFERENCE_INDEX]]{{\]}}
+; CHECK-SAME: foo{{$}}
+
+alias <t6> = <bar>
+; CHECK: (scl 69){{.*}}t6
+; CHECK-NEXT: AUX indx [[T6_DEFAULT_INDEX:[0-9]+]] srch 3
+; CHECK: {{^\[}}[[T6_DEFAULT_INDEX]]{{\]}}
+; CHECK-SAME: [[BAR_ADDRESS:0x[0-9a-fA-F]+]] .weak
+; CHECK: [[BAR_ADDRESS]] bar
+
+bar PROC
+  ret
+bar ENDP
+
+END
diff --git a/llvm/test/tools/llvm-ml/alias_errors.test b/llvm/test/tools/llvm-ml/alias_errors.test
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-ml/alias_errors.test
@@ -0,0 +1,36 @@
+; RUN: not llvm-ml -filetype=asm %s 2>&1 | FileCheck %s
+
+.code
+
+foo PROC
+  ret
+foo ENDP
+
+bar PROC
+  ret
+bar ENDP
+
+t1:
+alias foo = bar
+alias foo = <bar>
+alias <foo> = bar
+
+; CHECK: error: expected <aliasName>
+; CHECK: error: expected <aliasName>
+; CHECK: error: expected <actualName>
+
+t2:
+alias <foo> <bar>
+alias <foo>, <bar>
+
+; CHECK: error: unexpected token in alias directive
+; CHECK: error: unexpected token in alias directive
+
+t3:
+alias <foo = bar>
+alias <foo = bar
+
+; CHECK: error: unexpected token in alias directive
+; CHECK: error: expected <aliasName>
+
+END
\ No newline at end of file