diff --git a/mlir/include/mlir/Translation.h b/mlir/include/mlir/Translation.h
--- a/mlir/include/mlir/Translation.h
+++ b/mlir/include/mlir/Translation.h
@@ -101,8 +101,12 @@
 /// of tools like `mlir-translate`. The translation to perform is parsed from
 /// the command line. The `toolName` argument is used for the header displayed
 /// by `--help`.
-LogicalResult mlirTranslateMain(int argc, char **argv,
-                                llvm::StringRef toolName);
+///
+/// The client may specify a "customization" function if they'd like, which
+/// is invoked when an MLIRContext is set up, allowing custom settings.
+LogicalResult
+mlirTranslateMain(int argc, char **argv, llvm::StringRef toolName,
+                  std::function<void(MLIRContext &)> customization = {});
 
 } // namespace mlir
 
diff --git a/mlir/lib/Translation/Translation.cpp b/mlir/lib/Translation/Translation.cpp
--- a/mlir/lib/Translation/Translation.cpp
+++ b/mlir/lib/Translation/Translation.cpp
@@ -129,8 +129,9 @@
   llvm::cl::parser<const TranslateFunction *>::printOptionInfo(o, globalWidth);
 }
 
-LogicalResult mlir::mlirTranslateMain(int argc, char **argv,
-                                      llvm::StringRef toolName) {
+LogicalResult
+mlir::mlirTranslateMain(int argc, char **argv, llvm::StringRef toolName,
+                        std::function<void(MLIRContext &)> customization) {
 
   static llvm::cl::opt<std::string> inputFilename(
       llvm::cl::Positional, llvm::cl::desc("<input file>"),
@@ -184,8 +185,19 @@
   auto processBuffer = [&](std::unique_ptr<llvm::MemoryBuffer> ownedBuffer,
                            raw_ostream &os) {
     MLIRContext context;
-    context.allowUnregisteredDialects(allowUnregisteredDialects);
+
+    // If a customization callback was provided, apply it to the MLIRContext.
+    // This could add dialects to the registry or change context defaults.
+    if (customization)
+      customization(context);
+
+    // If command line flags were used to customize the context, apply their
+    // settings.
+    if (allowUnregisteredDialects.getNumOccurrences())
+      context.allowUnregisteredDialects(allowUnregisteredDialects);
+
     context.printOpOnDiagnostic(!verifyDiagnostics);
+
     llvm::SourceMgr sourceMgr;
     sourceMgr.AddNewSourceBuffer(std::move(ownedBuffer), SMLoc());