diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -6099,6 +6099,10 @@
   HelpText<"Deprecated (set output file name); use /Fe or /Fe">,
   MetaVarName<"<file or dir/>">;
 def _SLASH_P : CLFlag<"P">, HelpText<"Preprocess to file">;
+def _SLASH_permissive : CLFlag<"permissive">,
+  HelpText<"Enable some non conforming code to compile">;
+def _SLASH_permissive_ : CLFlag<"permissive-">,
+  HelpText<"Disable non conforming code from compiling (default)">;
 def _SLASH_Tc : CLCompileJoinedOrSeparate<"Tc">,
   HelpText<"Treat <file> as C source file">, MetaVarName<"<file>">;
 def _SLASH_TC : CLCompileFlag<"TC">, HelpText<"Treat all source files as C">;
@@ -6180,7 +6184,6 @@
 def _SLASH_JMC : CLIgnoredFlag<"JMC">;
 def _SLASH_kernel_ : CLIgnoredFlag<"kernel-">;
 def _SLASH_nologo : CLIgnoredFlag<"nologo">;
-def _SLASH_permissive_ : CLIgnoredFlag<"permissive-">;
 def _SLASH_RTC : CLIgnoredJoined<"RTC">;
 def _SLASH_sdl : CLIgnoredFlag<"sdl">;
 def _SLASH_sdl_ : CLIgnoredFlag<"sdl-">;
diff --git a/clang/lib/Driver/ToolChains/MSVC.cpp b/clang/lib/Driver/ToolChains/MSVC.cpp
--- a/clang/lib/Driver/ToolChains/MSVC.cpp
+++ b/clang/lib/Driver/ToolChains/MSVC.cpp
@@ -1523,6 +1523,20 @@
   DAL.AddJoinedArg(A, Opts.getOption(options::OPT_D), NewVal);
 }
 
+static void TranslatePermissive(Arg *A, llvm::opt::DerivedArgList &DAL,
+                                const OptTable &Opts) {
+  DAL.AddFlagArg(A, Opts.getOption(options::OPT__SLASH_Zc_twoPhase_));
+  DAL.AddFlagArg(A, Opts.getOption(options::OPT_fno_operator_names));
+  // There is currently no /Zc:strictStrings- in clang-cl
+}
+
+static void TranslatePermissiveMinus(Arg *A, llvm::opt::DerivedArgList &DAL,
+                                     const OptTable &Opts) {
+  DAL.AddFlagArg(A, Opts.getOption(options::OPT__SLASH_Zc_twoPhase));
+  DAL.AddFlagArg(A, Opts.getOption(options::OPT_foperator_names));
+  DAL.AddFlagArg(A, Opts.getOption(options::OPT__SLASH_Zc_strictStrings));
+}
+
 llvm::opt::DerivedArgList *
 MSVCToolChain::TranslateArgs(const llvm::opt::DerivedArgList &Args,
                              StringRef BoundArch,
@@ -1565,6 +1579,12 @@
     } else if (A->getOption().matches(options::OPT_D)) {
       // Translate -Dfoo#bar into -Dfoo=bar.
       TranslateDArg(A, *DAL, Opts);
+    } else if (A->getOption().matches(options::OPT__SLASH_permissive)) {
+      // Expand /permissive
+      TranslatePermissive(A, *DAL, Opts);
+    } else if (A->getOption().matches(options::OPT__SLASH_permissive_)) {
+      // Expand /permissive-
+      TranslatePermissiveMinus(A, *DAL, Opts);
     } else if (OFK != Action::OFK_HIP) {
       // HIP Toolchain translates input args by itself.
       DAL->append(A);
diff --git a/clang/test/Driver/cl-permissive.c b/clang/test/Driver/cl-permissive.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/cl-permissive.c
@@ -0,0 +1,17 @@
+// Note: %s must be preceded by --, otherwise it may be interpreted as a
+// command-line option, e.g. on Mac where %s is commonly under /Users.
+
+// RUN: %clang_cl /permissive -### -- %s 2>&1 | FileCheck -check-prefix=PERMISSIVE %s
+// PERMISSIVE: "-fno-operator-names"
+// PERMISSIVE: "-fdelayed-template-parsing"
+// RUN: %clang_cl /permissive- -### -- %s 2>&1 | FileCheck -check-prefix=PERMISSIVE-MINUS %s
+// PERMISSIVE-MINUS-NOT: "-fno-operator-names"
+// PERMISSIVE-MINUS-NOT: "-fdelayed-template-parsing"
+
+// The switches set by permissive may then still be manually enabled or disabled
+// RUN: %clang_cl /permissive /Zc:twoPhase -### -- %s 2>&1 | FileCheck -check-prefix=PERMISSIVE-OVERWRITE %s
+// PERMISSIVE-OVERWRITE: "-fno-operator-names"
+// PERMISSIVE-OVERWRITE-NOT: "-fdelayed-template-parsing"
+// RUN: %clang_cl /permissive- /Zc:twoPhase- -### -- %s 2>&1 | FileCheck -check-prefix=PERMISSIVE-MINUS-OVERWRITE %s
+// PERMISSIVE-MINUS-OVERWRITE-NOT: "-fno-operator-names"
+// PERMISSIVE-MINUS-OVERWRITE: "-fdelayed-template-parsing"