diff --git a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
--- a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
+++ b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
@@ -1151,7 +1151,8 @@
     auto n =
         std::min<size_t>(adaptor.getPosition().size(), vectorType.getRank());
     inferredReturnTypes.push_back(VectorType::get(
-        vectorType.getShape().drop_front(n), vectorType.getElementType()));
+        vectorType.getShape().drop_front(n), vectorType.getElementType(),
+        vectorType.getScalableDims().drop_front(n)));
   }
   return success();
 }
diff --git a/mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp b/mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp
--- a/mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp
+++ b/mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp
@@ -416,6 +416,18 @@
   }
 };
 
+/// Looks at elementwise operations on vectors with at least one leading
+/// dimension equal 1, e.g. vector<1x[4]x1xf32> (but not vector<2x[4]x1xf32>),
+/// and cast aways the leading one dimensions (_plural_) and then broadcasts
+/// the results.
+///
+/// Example before:
+///     %1 = arith.mulf %arg0, %arg1 : vector<1x4x1xf32>
+/// Example after:
+///    %2 = arith.mulf %0, %1 : vector<4x1xf32>
+///    %3 = vector.broadcast %2 : vector<4x1xf32> to vector<1x4x1xf32>
+///
+/// Does support scalable vectors.
 class CastAwayElementwiseLeadingOneDim : public RewritePattern {
 public:
   CastAwayElementwiseLeadingOneDim(MLIRContext *context,
diff --git a/mlir/test/Dialect/Vector/vector-dropleadunitdim-transforms.mlir b/mlir/test/Dialect/Vector/vector-dropleadunitdim-transforms.mlir
--- a/mlir/test/Dialect/Vector/vector-dropleadunitdim-transforms.mlir
+++ b/mlir/test/Dialect/Vector/vector-dropleadunitdim-transforms.mlir
@@ -276,6 +276,30 @@
   return %0: vector<1x1x4xf32>
 }
 
+// CHECK-LABEL:   func.func @cast_away_insert_leading_one_dims_scalar_scalable(
+// CHECK-SAME:    %[[S:.*]]: f32,
+// CHECK-SAME:    %[[V:.*]]: vector<1x1x[4]xf32>) -> vector<1x1x[4]xf32> {
+func.func @cast_away_insert_leading_one_dims_scalar_scalable(%s: f32, %v: vector<1x1x[4]xf32>) -> vector<1x1x[4]xf32> {
+// CHECK:           %[[EXTRACT:.*]] = vector.extract %[[V]][0, 0] : vector<1x1x[4]xf32>
+// CHECK:           %[[INSERT:.*]] = vector.insert %[[S]], %[[EXTRACT]] [0] : f32 into vector<[4]xf32>
+// CHECK:           %[[BCAST:.*]] = vector.broadcast %[[INSERT]] : vector<[4]xf32> to vector<1x1x[4]xf32>
+// CHECK:           return %[[BCAST]] : vector<1x1x[4]xf32>
+  %0 = vector.insert %s, %v [0, 0, 0] : f32 into vector<1x1x[4]xf32>
+  return %0: vector<1x1x[4]xf32>
+}
+
+// CHECK-LABEL:   func.func @cast_away_insert_leading_one_dims_scalar_skip_scalable_dim(
+// CHECK-SAME:    %[[S:.*]]: f32,
+// CHECK-SAME:    %[[V:.*]]: vector<1x[1]x4xf32>) -> vector<1x[1]x4xf32> {
+func.func @cast_away_insert_leading_one_dims_scalar_skip_scalable_dim(%s: f32, %v: vector<1x[1]x4xf32>) -> vector<1x[1]x4xf32> {
+// CHECK:           %[[EXTRACT:.*]] = vector.extract %[[V]][0] : vector<1x[1]x4xf32>
+// CHECK:           %[[INSERT:.*]] = vector.insert %[[S]], %[[EXTRACT]] [0, 0] : f32 into vector<[1]x4xf32>
+// CHECK:           %[[BCAST:.*]] = vector.broadcast %[[INSERT]] : vector<[1]x4xf32> to vector<1x[1]x4xf32>
+// CHECK:           return %[[BCAST]] : vector<1x[1]x4xf32>
+  %0 = vector.insert %s, %v [0, 0, 0] : f32 into vector<1x[1]x4xf32>
+  return %0: vector<1x[1]x4xf32>
+}
+
 // CHECK-LABEL: func @cast_away_insert_leading_one_dims_rank1
 //  CHECK-SAME: (%[[S:.+]]: vector<4xf32>, %[[V:.+]]: vector<1x1x4xf32>)
 //       CHECK:   %[[BCAST:.+]] = vector.broadcast %[[S]] : vector<4xf32> to vector<1x1x4xf32>
@@ -285,6 +309,16 @@
   return %0: vector<1x1x4xf32>
 }
 
+// CHECK-LABEL:   func.func @cast_away_insert_leading_one_dims_rank1_scalable(
+// CHECK-SAME:    %[[S:.*]]: vector<[4]xf32>,
+// CHECK-SAME:    %[[V:.*]]: vector<1x1x[4]xf32>) -> vector<1x1x[4]xf32> {
+// CHECK:           %[[BCAST:.*]] = vector.broadcast %[[S]] : vector<[4]xf32> to vector<1x1x[4]xf32>
+// CHECK:           return %[[BCAST]] : vector<1x1x[4]xf32>
+func.func @cast_away_insert_leading_one_dims_rank1_scalable(%s: vector<[4]xf32>, %v: vector<1x1x[4]xf32>) -> vector<1x1x[4]xf32> {
+  %0 = vector.insert %s, %v [0, 0] : vector<[4]xf32> into vector<1x1x[4]xf32>
+  return %0: vector<1x1x[4]xf32>
+}
+
 // CHECK-LABEL: func @cast_away_insert_leading_one_dims_rank2
 //  CHECK-SAME: (%[[S:.+]]: vector<1x4xf32>, %[[V:.+]]: vector<1x1x4xf32>)
 //       CHECK:   %[[EXTRACT:.+]] = vector.extract %[[S]][0] : vector<1x4xf32>
@@ -295,6 +329,17 @@
   return %0: vector<1x1x4xf32>
 }
 
+// CHECK-LABEL:   func.func @cast_away_insert_leading_one_dims_rank2_scalable(
+// CHECK-SAME:    %[[S:.*]]: vector<1x[4]xf32>,
+// CHECK-SAME:    %[[V:.*]]: vector<1x1x[4]xf32>) -> vector<1x1x[4]xf32> {
+// CHECK:           %[[EXTRACT:.*]] = vector.extract %[[S]][0] : vector<1x[4]xf32>
+// CHECK:           %[[BCAST:.*]] = vector.broadcast %[[EXTRACT]] : vector<[4]xf32> to vector<1x1x[4]xf32>
+// CHECK:           return %[[BCAST]] : vector<1x1x[4]xf32>
+func.func @cast_away_insert_leading_one_dims_rank2_scalable(%s: vector<1x[4]xf32>, %v: vector<1x1x[4]xf32>) -> vector<1x1x[4]xf32> {
+  %0 = vector.insert %s, %v [0] : vector<1x[4]xf32> into vector<1x1x[4]xf32>
+  return %0: vector<1x1x[4]xf32>
+}
+
 // CHECK-LABEL: func @cast_away_insert_leading_one_dims_rank2_one_dest
 //  CHECK-SAME: (%[[S:.+]]: vector<1x4xf32>, %[[V:.+]]: vector<1x2x1x4xf32>)
 //       CHECK:   %[[EXTRACTS:.+]] = vector.extract %[[S]][0] : vector<1x4xf32>
@@ -307,6 +352,19 @@
   return %0: vector<1x2x1x4xf32>
 }
 
+// CHECK-LABEL:   func.func @cast_away_insert_leading_one_dims_rank2_one_dest_scalable(
+// CHECK-SAME:      %[[S:.*]]: vector<1x[4]xf32>,
+// CHECK-SAME:      %[[V:.*]]: vector<1x2x1x[4]xf32>) -> vector<1x2x1x[4]xf32> {
+// CHECK:           %[[EXTRACTS:.*]] = vector.extract %[[S]][0] : vector<1x[4]xf32>
+// CHECK:           %[[EXTRACTV:.*]] = vector.extract %[[V]][0] : vector<1x2x1x[4]xf32>
+// CHECK:           %[[INSERT:.*]] = vector.insert %[[EXTRACTS]], %[[EXTRACTV]] [1, 0] : vector<[4]xf32> into vector<2x1x[4]xf32>
+// CHECK:           %[[BCAST:.*]] = vector.broadcast %[[INSERT]] : vector<2x1x[4]xf32> to vector<1x2x1x[4]xf32>
+// CHECK:           return %[[BCAST]] : vector<1x2x1x[4]xf32>
+func.func @cast_away_insert_leading_one_dims_rank2_one_dest_scalable(%s: vector<1x[4]xf32>, %v: vector<1x2x1x[4]xf32>) -> vector<1x2x1x[4]xf32> {
+  %0 = vector.insert %s, %v [0, 1] : vector<1x[4]xf32> into vector<1x2x1x[4]xf32>
+  return %0: vector<1x2x1x[4]xf32>
+}
+
 // CHECK-LABEL: func @cast_away_insert_leading_one_dims_non_one_dest
 //  CHECK-SAME: (%[[S:.+]]: vector<1x4xf32>, %[[V:.+]]: vector<8x1x4xf32>)
 //       CHECK:   %[[EXTRACT:.+]] = vector.extract %[[S]][0] : vector<1x4xf32>
@@ -317,6 +375,17 @@
   return %0: vector<8x1x4xf32>
 }
 
+// CHECK-LABEL:   func.func @cast_away_insert_leading_one_dims_non_one_dest_scalable(
+// CHECK-SAME:      %[[S:.*]]: vector<1x[4]xf32>,
+// CHECK-SAME:      %[[V:.*]]: vector<8x1x[4]xf32>) -> vector<8x1x[4]xf32> {
+// CHECK:           %[[EXTRACT:.*]] = vector.extract %[[S]][0] : vector<1x[4]xf32>
+// CHECK:           %[[INSERT:.*]] = vector.insert %[[EXTRACT]], %[[V]] [5, 0] : vector<[4]xf32> into vector<8x1x[4]xf32>
+// CHECK:           return %[[INSERT]] : vector<8x1x[4]xf32>
+func.func @cast_away_insert_leading_one_dims_non_one_dest_scalable(%s: vector<1x[4]xf32>, %v: vector<8x1x[4]xf32>) -> vector<8x1x[4]xf32> {
+  %0 = vector.insert %s, %v [5] : vector<1x[4]xf32> into vector<8x1x[4]xf32>
+  return %0: vector<8x1x[4]xf32>
+}
+
 // CHECK-LABEL: func @cast_away_insert_leading_one_dims_one_two_dest
 //  CHECK-SAME: (%[[S:.+]]: vector<1x8xi1>, %[[V:.+]]: vector<1x1x8x1x8xi1>)
 //       CHECK:   %[[EXTRACTS:.+]] = vector.extract %[[S]][0] : vector<1x8xi1>
@@ -328,3 +397,16 @@
   %0 = vector.insert %s, %v [0, 0, 7] : vector<1x8xi1> into vector<1x1x8x1x8xi1>
   return %0: vector<1x1x8x1x8xi1>
 }
+
+// CHECK-LABEL:   func.func @cast_away_insert_leading_one_dims_one_two_dest_scalable(
+// CHECK-SAME:      %[[S:.*]]: vector<1x[8]xi1>,
+// CHECK-SAME:      %[[V:.*]]: vector<1x1x8x1x[8]xi1>) -> vector<1x1x8x1x[8]xi1> {
+// CHECK:           %[[EXTRACTS:.*]] = vector.extract %[[S]][0] : vector<1x[8]xi1>
+// CHECK:           %[[EXTRACTV:.*]] = vector.extract %[[V]][0, 0] : vector<1x1x8x1x[8]xi1>
+// CHECK:           %[[INSERT:.*]] = vector.insert %[[EXTRACTS]], %[[EXTRACTV]] [7, 0] : vector<[8]xi1> into vector<8x1x[8]xi1>
+// CHECK:           %[[BCAST:.*]] = vector.broadcast %[[INSERT]] : vector<8x1x[8]xi1> to vector<1x1x8x1x[8]xi1>
+// CHECK:           return %[[BCAST]] : vector<1x1x8x1x[8]xi1>
+func.func @cast_away_insert_leading_one_dims_one_two_dest_scalable(%s: vector<1x[8]xi1>, %v: vector<1x1x8x1x[8]xi1>) -> vector<1x1x8x1x[8]xi1> {
+  %0 = vector.insert %s, %v [0, 0, 7] : vector<1x[8]xi1> into vector<1x1x8x1x[8]xi1>
+  return %0: vector<1x1x8x1x[8]xi1>
+}
diff --git a/mlir/test/Dialect/Vector/vector-transforms.mlir b/mlir/test/Dialect/Vector/vector-transforms.mlir
--- a/mlir/test/Dialect/Vector/vector-transforms.mlir
+++ b/mlir/test/Dialect/Vector/vector-transforms.mlir
@@ -34,6 +34,22 @@
   return %1 : vector<2x[4]x1xf32>
 }
 
+// CHECK-LABEL:   func.func @cast_away_leading_one_dim(
+// CHECK:           %[[MUL:.*]] = arith.mulf %{{.*}}, %{{.*}} : vector<4x1xf32>
+// CHECK:           vector.broadcast %[[MUL]] : vector<4x1xf32> to vector<1x4x1xf32>
+func.func @cast_away_leading_one_dim(%arg0: vector<1x4x1xf32>, %arg1: vector<1x4x1xf32>) -> vector<1x4x1xf32> {
+  %1 = arith.mulf %arg0, %arg1 : vector<1x4x1xf32>
+  return %1: vector<1x4x1xf32>
+}
+
+// CHECK-LABEL:   func.func @cast_away_leading_one_dim_scalable(
+// CHECK:           %[[MUL:.*]] = arith.mulf %{{.*}}, %{{.*}} : vector<[4]x1xf32>
+// CHECK:           vector.broadcast %[[MUL]] : vector<[4]x1xf32> to vector<1x[4]x1xf32>
+func.func @cast_away_leading_one_dim_scalable(%arg0: vector<1x[4]x1xf32>, %arg1: vector<1x[4]x1xf32>) -> vector<1x[4]x1xf32> {
+  %1 = arith.mulf %arg0, %arg1 : vector<1x[4]x1xf32>
+  return %1: vector<1x[4]x1xf32>
+}
+
 // CHECK-LABEL: func @add4x4
 //      CHECK: %[[S1:.*]] = vector.extract_strided_slice %{{.*}} {offsets = [0, 0], sizes = [2, 2], strides = [1, 1]} : vector<4x4xf32> to vector<2x2xf32>
 // CHECK-NEXT: %[[S2:.*]] = vector.extract_strided_slice %{{.*}} {offsets = [0, 0], sizes = [2, 2], strides = [1, 1]} : vector<4x4xf32> to vector<2x2xf32>