diff --git a/mlir/include/mlir/Dialect/DXSA/IR/DXSAOps.td b/mlir/include/mlir/Dialect/DXSA/IR/DXSAOps.td
index ed5a295a38db..9bb4cf55ed7f 100644
--- a/mlir/include/mlir/Dialect/DXSA/IR/DXSAOps.td
+++ b/mlir/include/mlir/Dialect/DXSA/IR/DXSAOps.td
@@ -719,4 +719,28 @@ def DXSA_DclOutput : DXSA_Op<"dcl_output"> {
   let assemblyFormat = "$operand attr-dict";
 }
 
+def DXSA_DclThreadGroup : DXSA_Op<"dcl_thread_group"> {
+  let summary = "declares compute shader thread group dimensions";
+  let description = [{
+    The `dxsa.dcl_thread_group` operation declares the `$x`, `$y` and `$z`
+    dimensions of a compute shader thread group.
+
+    The product `$x` * `$y` * `$z` must not exceed 1024.
+
+    Example:
+
+    ```mlir
+    dxsa.dcl_thread_group<x = 1, y = 1, z = 1>
+    ```
+  }];
+  let arguments = (ins
+      ConfinedAttr<I32Attr, [IntPositive, IntMaxValue<1024>]>:$x,
+      ConfinedAttr<I32Attr, [IntPositive, IntMaxValue<1024>]>:$y,
+      ConfinedAttr<I32Attr, [IntPositive, IntMaxValue<64>]>:$z);
+  let assemblyFormat = [{
+    `<` `x` `=` $x `,` `y` `=` $y `,` `z` `=` $z `>` attr-dict
+  }];
+  let hasVerifier = 1;
+}
+
 #endif // DXSA_OPS
diff --git a/mlir/lib/Dialect/DXSA/IR/DXSA.cpp b/mlir/lib/Dialect/DXSA/IR/DXSA.cpp
index e5c94051e3a5..f49027a07fb8 100644
--- a/mlir/lib/Dialect/DXSA/IR/DXSA.cpp
+++ b/mlir/lib/Dialect/DXSA/IR/DXSA.cpp
@@ -34,6 +34,19 @@ void DXSADialect::initialize() {
       >();
 }
 
+//===----------------------------------------------------------------------===//
+// DclThreadGroup
+//===----------------------------------------------------------------------===//
+
+LogicalResult DclThreadGroup::verify() {
+  constexpr int64_t maxTotalThreads = 1024;
+  if (auto total = static_cast<int64_t>(getX()) * getY() * getZ();
+      total > maxTotalThreads)
+    return emitOpError("thread group size x*y*z must be <= ")
+           << maxTotalThreads << ", got " << total;
+  return success();
+}
+
 //===----------------------------------------------------------------------===//
 // TableGen'd op method definitions
 //===----------------------------------------------------------------------===//
diff --git a/mlir/lib/Target/DXSA/BinaryParser.cpp b/mlir/lib/Target/DXSA/BinaryParser.cpp
index f1c860c758a2..225a8cd17ffd 100644
--- a/mlir/lib/Target/DXSA/BinaryParser.cpp
+++ b/mlir/lib/Target/DXSA/BinaryParser.cpp
@@ -635,6 +635,13 @@ class DXBuilder {
     return dxsa::DclOutput::create(builder, loc, operand);
   }
 
+  Instruction buildDclThreadGroup(uint32_t x, uint32_t y, uint32_t z,
+                                  Location loc) {
+    return dxsa::DclThreadGroup::create(
+        builder, loc, builder.getI32IntegerAttr(x),
+        builder.getI32IntegerAttr(y), builder.getI32IntegerAttr(z));
+  }
+
 private:
   MLIRContext *context;
   ModuleOp module;
@@ -1174,6 +1181,16 @@ class Parser {
     return builder.buildDclOutput(*operand, loc);
   }
 
+  FailureOr<Instruction> parseDclThreadGroup(Location loc) {
+    auto x = parseToken();
+    FAILURE_IF_FAILED(x);
+    auto y = parseToken();
+    FAILURE_IF_FAILED(y);
+    auto z = parseToken();
+    FAILURE_IF_FAILED(z);
+    return builder.buildDclThreadGroup(*x, *y, *z, loc);
+  }
+
   OptionalParseResult parseDclInstruction(uint32_t opcodeToken, Location loc,
                                           Instruction &out) {
     FailureOr<Instruction> result;
@@ -1220,6 +1237,9 @@ class Parser {
     case D3D10_SB_OPCODE_DCL_OUTPUT:
       result = parseDclOutput(loc);
       break;
+    case D3D11_SB_OPCODE_DCL_THREAD_GROUP:
+      result = parseDclThreadGroup(loc);
+      break;
     default:
       return std::nullopt;
     }
diff --git a/mlir/test/Target/DXSA/dcl_thread_group.mlir b/mlir/test/Target/DXSA/dcl_thread_group.mlir
new file mode 100644
index 000000000000..ef296ba4130b
--- /dev/null
+++ b/mlir/test/Target/DXSA/dcl_thread_group.mlir
@@ -0,0 +1,8 @@
+// RUN: mlir-translate --import-dxsa-bin %S/inputs/dcl_thread_group.bin | FileCheck %s
+
+// CHECK:      module {
+// CHECK-NEXT:   dxsa.dcl_thread_group<x = 1, y = 1, z = 1>
+// CHECK-NEXT:   dxsa.dcl_thread_group<x = 1024, y = 1, z = 1>
+// CHECK-NEXT:   dxsa.dcl_thread_group<x = 1, y = 1024, z = 1>
+// CHECK-NEXT:   dxsa.dcl_thread_group<x = 1, y = 1, z = 64>
+// CHECK-NEXT: }
diff --git a/mlir/test/Target/DXSA/dcl_thread_group_invalid.mlir b/mlir/test/Target/DXSA/dcl_thread_group_invalid.mlir
new file mode 100644
index 000000000000..17b1be8587aa
--- /dev/null
+++ b/mlir/test/Target/DXSA/dcl_thread_group_invalid.mlir
@@ -0,0 +1,35 @@
+// RUN: mlir-opt %s -split-input-file -verify-diagnostics
+
+// expected-error@+1 {{attribute 'x' failed to satisfy constraint: 32-bit signless integer attribute whose value is positive whose maximum value is 1024}}
+dxsa.dcl_thread_group <x = 0, y = 1, z = 1>
+
+// -----
+
+// expected-error@+1 {{attribute 'x' failed to satisfy constraint: 32-bit signless integer attribute whose value is positive whose maximum value is 1024}}
+dxsa.dcl_thread_group <x = 1025, y = 1, z = 1>
+
+// -----
+
+// expected-error@+1 {{attribute 'y' failed to satisfy constraint: 32-bit signless integer attribute whose value is positive whose maximum value is 1024}}
+dxsa.dcl_thread_group <x = 1, y = 0, z = 1>
+
+// -----
+
+// expected-error@+1 {{attribute 'y' failed to satisfy constraint: 32-bit signless integer attribute whose value is positive whose maximum value is 1024}}
+dxsa.dcl_thread_group <x = 1, y = 1025, z = 1>
+
+// -----
+
+// expected-error@+1 {{attribute 'z' failed to satisfy constraint: 32-bit signless integer attribute whose value is positive whose maximum value is 64}}
+dxsa.dcl_thread_group <x = 1, y = 1, z = 0>
+
+// -----
+
+// expected-error@+1 {{attribute 'z' failed to satisfy constraint: 32-bit signless integer attribute whose value is positive whose maximum value is 64}}
+dxsa.dcl_thread_group <x = 1, y = 1, z = 65>
+
+// -----
+
+// 64 * 8 * 4 == 2048
+// expected-error@+1 {{'dxsa.dcl_thread_group' op thread group size x*y*z must be <= 1024, got 2048}}
+dxsa.dcl_thread_group <x = 64, y = 8, z = 4>
diff --git a/mlir/test/Target/DXSA/inputs/dcl_thread_group.bin b/mlir/test/Target/DXSA/inputs/dcl_thread_group.bin
new file mode 100644
index 000000000000..f478f3ed7a8d
Binary files /dev/null and b/mlir/test/Target/DXSA/inputs/dcl_thread_group.bin differ