diff --git a/mlir/test/mlir-tblgen/op-interface.td b/mlir/test/mlir-tblgen/op-interface.td
--- a/mlir/test/mlir-tblgen/op-interface.td
+++ b/mlir/test/mlir-tblgen/op-interface.td
@@ -73,6 +73,7 @@
 // DECL-LABEL: TestOpInterfaceInterfaceTraits
 // DECL: class TestOpInterface : public ::mlir::OpInterface<TestOpInterface, detail::TestOpInterfaceInterfaceTraits>
 
+// DECL: /// some function comment
 // DECL: int foo(int input);
 
 // DECL: template<typename ConcreteOp>
diff --git a/mlir/tools/mlir-tblgen/DocGenUtilities.h b/mlir/tools/mlir-tblgen/DocGenUtilities.h
--- a/mlir/tools/mlir-tblgen/DocGenUtilities.h
+++ b/mlir/tools/mlir-tblgen/DocGenUtilities.h
@@ -14,9 +14,10 @@
 #ifndef MLIR_TOOLS_MLIRTBLGEN_DOCGENUTILITIES_H_
 #define MLIR_TOOLS_MLIRTBLGEN_DOCGENUTILITIES_H_
 
+#include "llvm/ADT/StringRef.h"
+
 namespace llvm {
 class raw_ostream;
-class StringRef;
 } // namespace llvm
 
 namespace mlir {
@@ -30,6 +31,10 @@
 // nested.
 void emitDescription(llvm::StringRef description, llvm::raw_ostream &os);
 
+// Emit the description as a C++ comment while realigning it.
+void emitDescriptionComment(llvm::StringRef description, llvm::raw_ostream &os,
+                            llvm::StringRef prefix = "");
+
 } // namespace tblgen
 } // namespace mlir
 
diff --git a/mlir/tools/mlir-tblgen/OpDocGen.cpp b/mlir/tools/mlir-tblgen/OpDocGen.cpp
--- a/mlir/tools/mlir-tblgen/OpDocGen.cpp
+++ b/mlir/tools/mlir-tblgen/OpDocGen.cpp
@@ -48,6 +48,24 @@
   ros.printReindented(description.rtrim(" \t"));
 }
 
+void mlir::tblgen::emitDescriptionComment(StringRef description,
+                                          raw_ostream &os, StringRef prefix) {
+  // Split the description string at newline and drop leading and trailing empty
+  // strings, but not the intermediate empty strings that may help with comment
+  // readability.
+  SmallVector<StringRef> parts;
+  description.split(parts, '\n');
+  ArrayRef<StringRef> partsRef = llvm::makeArrayRef(parts);
+  while (!partsRef.empty() && partsRef.front().trim().empty()) {
+    partsRef = partsRef.drop_front();
+  }
+  while (!partsRef.empty() && partsRef.back().trim().empty())
+    partsRef = partsRef.drop_back();
+
+  for (StringRef part : partsRef)
+    os << prefix << "/// " << part.trim() << "\n";
+}
+
 // Emits `str` with trailing newline if not empty.
 static void emitIfNotEmpty(StringRef str, raw_ostream &os) {
   if (!str.empty()) {
diff --git a/mlir/tools/mlir-tblgen/OpInterfacesGen.cpp b/mlir/tools/mlir-tblgen/OpInterfacesGen.cpp
--- a/mlir/tools/mlir-tblgen/OpInterfacesGen.cpp
+++ b/mlir/tools/mlir-tblgen/OpInterfacesGen.cpp
@@ -158,6 +158,12 @@
 // GEN: Interface definitions
 //===----------------------------------------------------------------------===//
 
+static void emitInterfaceMethodDoc(const InterfaceMethod &method,
+                                   raw_ostream &os, StringRef prefix = "") {
+  if (Optional<StringRef> description = method.getDescription())
+    tblgen::emitDescriptionComment(*description, os, prefix);
+}
+
 static void emitInterfaceDef(const Interface &interface, StringRef valueType,
                              raw_ostream &os) {
   StringRef interfaceName = interface.getName();
@@ -167,6 +173,7 @@
   // Insert the method definitions.
   bool isOpInterface = isa<OpInterface>(interface);
   for (auto &method : interface.getMethods()) {
+    emitInterfaceMethodDoc(method, os);
     emitCPPType(method.getReturnType(), os);
     if (!cppNamespace.empty())
       os << cppNamespace << "::";
@@ -401,6 +408,7 @@
     if (!defaultImpl)
       continue;
 
+    emitInterfaceMethodDoc(method, os, "    ");
     os << "    " << (method.isStatic() ? "static " : "");
     emitCPPType(method.getReturnType(), os);
     emitMethodNameAndArgs(method, os, valueType, /*addThisArg=*/false,
@@ -470,6 +478,7 @@
   // Insert the method declarations.
   bool isOpInterface = isa<OpInterface>(interface);
   for (auto &method : interface.getMethods()) {
+    emitInterfaceMethodDoc(method, os, "  ");
     emitCPPType(method.getReturnType(), os << "  ");
     emitMethodNameAndArgs(method, os, valueType, /*addThisArg=*/false,
                           /*addConst=*/!isOpInterface);