diff --git a/clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp b/clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp
--- a/clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp
@@ -8,6 +8,7 @@
 
 #include "UnusedParametersCheck.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTLambda.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/Lex/Lexer.h"
@@ -141,7 +142,8 @@
   // Cannot remove parameter for non-local functions.
   if (Function->isExternallyVisible() ||
       !Result.SourceManager->isInMainFile(Function->getLocation()) ||
-      !Indexer->getOtherRefs(Function).empty() || isOverrideMethod(Function)) {
+      !Indexer->getOtherRefs(Function).empty() || isOverrideMethod(Function) ||
+      isLambdaCallOperator(Function)) {
 
     // It is illegal to omit parameter name here in C code, so early-out.
     if (!Result.Context->getLangOpts().CPlusPlus)
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc-unused-parameters.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc-unused-parameters.cpp
--- a/clang-tools-extra/test/clang-tidy/checkers/misc-unused-parameters.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc-unused-parameters.cpp
@@ -276,3 +276,13 @@
 // CHECK-FIXES: {{^}}  B(int  /*i*/) : A() {}{{$}}
 };
 } // namespace strict_mode_off
+
+namespace lambda {
+using fn = void(int);
+void f(fn *);
+void test() {
+  // CHECK-MESSAGES: :[[@LINE+2]]:12: warning: parameter 'I' is unused
+  // CHECK-FIXES: {{^}}  f([](int  /*I*/) {
+  f([](int I) { return; });
+}
+} // namespace lambda