Index: mlir/lib/Dialect/Vector/IR/VectorOps.cpp
===================================================================
--- mlir/lib/Dialect/Vector/IR/VectorOps.cpp
+++ mlir/lib/Dialect/Vector/IR/VectorOps.cpp
@@ -2650,10 +2650,18 @@
   if (!vLHS)
     return parser.emitError(parser.getNameLoc(),
                             "expected vector type for operand #1");
-  VectorType resType =
-      vRHS ? VectorType::get({vLHS.getDimSize(0), vRHS.getDimSize(0)},
-                             vLHS.getElementType())
-           : VectorType::get({vLHS.getDimSize(0)}, vLHS.getElementType());
+
+  unsigned numScalableDims = vLHS.getNumScalableDims();
+  VectorType resType;
+  if (vRHS) {
+    numScalableDims += vRHS.getNumScalableDims();
+    resType = VectorType::get({vLHS.getDimSize(0), vRHS.getDimSize(0)},
+                              vLHS.getElementType(), numScalableDims);
+  } else {
+    // Scalar RHS operand
+    resType = VectorType::get({vLHS.getDimSize(0)}, vLHS.getElementType(),
+                              numScalableDims);
+  }
 
   if (!result.attributes.get(OuterProductOp::getKindAttrStrName())) {
     result.attributes.append(
@@ -2689,6 +2697,9 @@
       return emitOpError("expected #1 operand dim to match result dim #1");
     if (vRHS.getDimSize(0) != vRES.getDimSize(1))
       return emitOpError("expected #2 operand dim to match result dim #2");
+    if (vRHS.isScalable() != vLHS.isScalable())
+      return emitOpError("expected either all or none of vector operands #1 "
+                         "and #2 to be scalable");
   } else {
     // An AXPY operation.
     if (vRES.getRank() != 1)
Index: mlir/test/Dialect/Vector/vector-scalable-outerproduct.mlir
===================================================================
--- /dev/null
+++ mlir/test/Dialect/Vector/vector-scalable-outerproduct.mlir
@@ -0,0 +1,36 @@
+// RUN: mlir-opt -split-input-file -verify-diagnostics %s | mlir-opt
+
+func.func @scalable_outerproduct(%src : memref<?xf32>) {
+  %idx = arith.constant 0 : index
+  %cst = arith.constant 1.0 : f32
+  %0 = vector.load %src[%idx] : memref<?xf32>, vector<[4]xf32>
+  %1 = vector.load %src[%idx] : memref<?xf32>, vector<[4]xf32>
+
+  %op = vector.outerproduct %0, %1 : vector<[4]xf32>, vector<[4]xf32>
+  vector.store %op, %src[%idx] : memref<?xf32>, vector<[4x4]xf32>
+
+  %op2 = vector.outerproduct %0, %cst : vector<[4]xf32>, f32
+  vector.store %op2, %src[%idx] : memref<?xf32>, vector<[4]xf32>
+  return
+}
+
+// -----
+
+func.func @invalid_outerproduct(%src : memref<?xf32>) {
+  %idx = arith.constant 0 : index
+  %0 = vector.load %src[%idx] : memref<?xf32>, vector<[4]xf32>
+  %1 = vector.load %src[%idx] : memref<?xf32>, vector<4xf32>
+
+  // expected-error @+1 {{expected either all or none of vector operands #1 and #2 to be scalable}}
+  %op = vector.outerproduct %0, %1 : vector<[4]xf32>, vector<4xf32>
+}
+// -----
+
+func.func @invalid_outerproduct1(%src : memref<?xf32>) {
+  %idx = arith.constant 0 : index
+  %0 = vector.load %src[%idx] : memref<?xf32>, vector<[4x4]xf32>
+  %1 = vector.load %src[%idx] : memref<?xf32>, vector<[4]xf32>
+
+  // expected-error @+1 {{expected 1-d vector for operand #1}}
+  %op = vector.outerproduct %0, %1 : vector<[4x4]xf32>, vector<[4]xf32>
+}