diff --git a/mlir/include/mlir-c/IR.h b/mlir/include/mlir-c/IR.h
--- a/mlir/include/mlir-c/IR.h
+++ b/mlir/include/mlir-c/IR.h
@@ -147,6 +147,10 @@
 MLIR_CAPI_EXPORTED MlirLocation mlirLocationFileLineColGet(
     MlirContext context, MlirStringRef filename, unsigned line, unsigned col);
 
+/// Creates a call site location with a callee and a caller.
+MLIR_CAPI_EXPORTED MlirLocation mlirLocationCallSiteGet(MlirLocation callee,
+                                                        MlirLocation caller);
+
 /// Creates a location with unknown position owned by the given context.
 MLIR_CAPI_EXPORTED MlirLocation mlirLocationUnknownGet(MlirContext context);
 
diff --git a/mlir/lib/CAPI/IR/IR.cpp b/mlir/lib/CAPI/IR/IR.cpp
--- a/mlir/lib/CAPI/IR/IR.cpp
+++ b/mlir/lib/CAPI/IR/IR.cpp
@@ -116,6 +116,10 @@
       FileLineColLoc::get(unwrap(filename), line, col, unwrap(context)));
 }
 
+MlirLocation mlirLocationCallSiteGet(MlirLocation callee, MlirLocation caller) {
+  return wrap(CallSiteLoc::get(unwrap(callee), unwrap(caller)));
+}
+
 MlirLocation mlirLocationUnknownGet(MlirContext context) {
   return wrap(UnknownLoc::get(unwrap(context)));
 }
diff --git a/mlir/test/CAPI/ir.c b/mlir/test/CAPI/ir.c
--- a/mlir/test/CAPI/ir.c
+++ b/mlir/test/CAPI/ir.c
@@ -1295,7 +1295,7 @@
   MlirLocation loc = mlirDiagnosticGetLocation(diagnostic);
   mlirLocationPrint(loc, printToStderr, NULL);
   assert(mlirDiagnosticGetNumNotes(diagnostic) == 0);
-  fprintf(stderr, ">> end of diagnostic (userData: %ld)\n", (long)userData);
+  fprintf(stderr, "\n>> end of diagnostic (userData: %ld)\n", (long)userData);
   return mlirLogicalResultSuccess();
 }
 
@@ -1308,16 +1308,32 @@
   MlirContext ctx = mlirContextCreate();
   MlirDiagnosticHandlerID id = mlirContextAttachDiagnosticHandler(
       ctx, errorHandler, (void *)42, deleteUserData);
-  MlirLocation loc = mlirLocationUnknownGet(ctx);
   fprintf(stderr, "@test_diagnostics\n");
-  mlirEmitError(loc, "test diagnostics");
+  MlirLocation unknownLoc = mlirLocationUnknownGet(ctx);
+  mlirEmitError(unknownLoc, "test diagnostics");
+  MlirLocation fileLineColLoc = mlirLocationFileLineColGet(
+      ctx, mlirStringRefCreateFromCString("file.c"), 1, 2);
+  mlirEmitError(fileLineColLoc, "test diagnostics");
+  MlirLocation callSiteLoc = mlirLocationCallSiteGet(
+      mlirLocationFileLineColGet(
+          ctx, mlirStringRefCreateFromCString("other-file.c"), 2, 3),
+      fileLineColLoc);
+  mlirEmitError(callSiteLoc, "test diagnostics");
   mlirContextDetachDiagnosticHandler(ctx, id);
-  mlirEmitError(loc, "more test diagnostics");
+  mlirEmitError(unknownLoc, "more test diagnostics");
   // CHECK-LABEL: @test_diagnostics
   // CHECK: processing diagnostic (userData: 42) <<
   // CHECK:   test diagnostics
   // CHECK:   loc(unknown)
   // CHECK: >> end of diagnostic (userData: 42)
+  // CHECK: processing diagnostic (userData: 42) <<
+  // CHECK:   test diagnostics
+  // CHECK:   loc("file.c":1:2)
+  // CHECK: >> end of diagnostic (userData: 42)
+  // CHECK: processing diagnostic (userData: 42) <<
+  // CHECK:   test diagnostics
+  // CHECK:   loc(callsite("other-file.c":2:3 at "file.c":1:2))
+  // CHECK: >> end of diagnostic (userData: 42)
   // CHECK: deleting user data (userData: 42)
   // CHECK-NOT: processing diagnostic
   // CHECK:     more test diagnostics