diff --git a/backends/qualcomm/runtime/targets.bzl b/backends/qualcomm/runtime/targets.bzl
index 5ad312020be..03323422238 100644
--- a/backends/qualcomm/runtime/targets.bzl
+++ b/backends/qualcomm/runtime/targets.bzl
@@ -3,6 +3,7 @@ load(
     "ANDROID",
     "CXX",
 )
+load("@fbsource//tools/build_defs:fbsource_utils.bzl", "is_fbcode")
 load("@fbsource//xplat/executorch/build:runtime_wrapper.bzl", "runtime")
 load("@fbsource//xplat/executorch/backends/qualcomm/third-party:third_party_libs.bzl", "qnn_third_party_dep")
 
@@ -55,7 +56,9 @@ def define_common_targets():
         },
         header_namespace = "",
         define_static_target = True,
-        platforms = [ANDROID],
+        # CXX (host) is only needed for the internal fbcode x86 QNN simulator
+        # test runner; OSS host builds (incl. macOS) never build this.
+        platforms = [ANDROID, CXX] if is_fbcode() else [ANDROID],
         visibility = ["PUBLIC"],
     )
 
diff --git a/backends/qualcomm/tests/BUCK b/backends/qualcomm/tests/BUCK
index c73a8f89536..e572a88b9c4 100644
--- a/backends/qualcomm/tests/BUCK
+++ b/backends/qualcomm/tests/BUCK
@@ -87,3 +87,29 @@ fbcode_target(_kind = runtime.python_test,
         "//executorch/examples/qualcomm/oss_scripts/llama:static_llama",
     ]),
 )
+
+# Runs the QNN operator tests on the x86_64 host simulator under buck. Internal
+# only: the underlying :test_qnn_delegate library pulls in caffe2/torchvision/etc
+# that are unavailable in OSS Buck (see the comment on that target), and keeping
+# it out of the OSS graph preserves the `test-qnn-buck-build-linux` CI signal.
+# The host qnn_executor_runner binary and the QNN x86 SDK libs are supplied via
+# env; the test reads QNN_EXECUTOR_RUNNER/QNN_SDK_ROOT and runs the simulator.
+None if runtime.is_oss else fbcode_target(
+    _kind = runtime.python_test,
+    name = "test_qnn_delegate_x86",
+    srcs = [
+        "test_qnn_delegate_x86.py",
+    ],
+    env = {
+        # Force CPU: quantization calibration, AOT compile, and the x86 HTP sim
+        # all run on CPU. Without this, parallel test shards each grab CUDA and
+        # exhaust GPU memory ("CUDA error: out of memory").
+        "CUDA_VISIBLE_DEVICES": "",
+        "LD_LIBRARY_PATH": "$(location fbsource//third-party/qualcomm/qnn/qnn-{0}:qnn_offline_compile_libs)".format(get_qnn_library_version()),
+        "QNN_EXECUTOR_RUNNER": "$(location //executorch/examples/qualcomm/executor_runner:qnn_executor_runner)",
+        "QNN_SDK_ROOT": "$(location fbsource//third-party/qualcomm/qnn/qnn-{0}:__dir__)".format(get_qnn_library_version()),
+    },
+    deps = [
+        ":test_qnn_delegate",
+    ],
+)
diff --git a/backends/qualcomm/tests/test_qnn_delegate_x86.py b/backends/qualcomm/tests/test_qnn_delegate_x86.py
new file mode 100644
index 00000000000..a687f1a334f
--- /dev/null
+++ b/backends/qualcomm/tests/test_qnn_delegate_x86.py
@@ -0,0 +1,47 @@
+# Copyright (c) Qualcomm Innovation Center, Inc.
+# All rights reserved
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+"""
+Buck-native entry point that runs the QNN operator tests on the x86_64 host
+simulator (no connected device, no CMake build tree).
+
+The full ``test_qnn_delegate.py`` suite is normally driven by its argparse
+``__main__`` block (``setup_environment``). That block never executes under a
+Buck ``python_test`` runner -- Buck imports the module and runs the discovered
+``TestCase`` subclasses directly -- so the flags that select host simulation
+(``--enable_x86_64``, ``--soc_model``, ``--backend``) are never parsed. This
+module re-exports the operator test classes and sets the equivalent ``TestQNN``
+class attributes at import time so the same tests run unmodified under
+``buck test``.
+
+The QNN x86 SDK libraries and the host ``qnn_executor_runner`` binary are
+provided by the Buck target's ``env`` (``QNN_SDK_ROOT``, ``LD_LIBRARY_PATH``,
+``QNN_EXECUTOR_RUNNER``); see the ``test_qnn_delegate_x86`` target in BUCK.
+"""
+
+import os
+
+from executorch.backends.qualcomm.tests import test_qnn_delegate as _ops
+from executorch.backends.qualcomm.tests.utils import TestQNN
+
+# Compile ahead-of-time and execute through the x86 simulator (qnn_executor_runner)
+# instead of pushing to a device over adb.
+TestQNN.enable_x86_64 = True
+TestQNN.backend = os.environ.get("QNN_BACKEND", "htp")
+# Only selects the HTP architecture baked into the offline-compiled context
+# binary; the x86 simulator runs the same graph regardless of the physical SoC.
+TestQNN.soc_model = os.environ.get("QNN_SOC_MODEL", "SM8650")
+
+
+# Subclass (rather than re-import) so the test runner discovers these classes as
+# defined in this module. The base classes stay behind the `_ops` module handle
+# so they are not collected (and double-run) from this module's namespace.
+class TestQNNFloatingPointOperator(_ops.TestQNNFloatingPointOperator):
+    pass
+
+
+class TestQNNQuantizedOperator(_ops.TestQNNQuantizedOperator):
+    pass
diff --git a/examples/qualcomm/executor_runner/targets.bzl b/examples/qualcomm/executor_runner/targets.bzl
index 5d60249b2f6..89a723bb35b 100644
--- a/examples/qualcomm/executor_runner/targets.bzl
+++ b/examples/qualcomm/executor_runner/targets.bzl
@@ -1,6 +1,7 @@
 load(
     "@fbsource//tools/build_defs:default_platform_defs.bzl",
     "ANDROID",
+    "CXX",
 )
 load("@fbsource//tools/build_defs:fbsource_utils.bzl", "is_fbcode")
 load("@fbsource//xplat/executorch/build:runtime_wrapper.bzl", "runtime")
@@ -23,6 +24,7 @@ def define_common_targets():
             "//executorch/runtime/executor:program",
             "//executorch/devtools/etdump:etdump_flatcc",
             "//executorch/devtools/bundled_program:runtime",
+            "//executorch/kernels/portable:generated_lib",
             "//executorch/kernels/quantized:generated_lib",
             "//executorch/extension/data_loader:buffer_data_loader",
             "//executorch/extension/data_loader:file_data_loader",
@@ -30,7 +32,11 @@ def define_common_targets():
             "//executorch/extension/runner_util:inputs",
             "//executorch/backends/qualcomm/runtime:runtime",
         ],
-        platforms = [ANDROID],
+        # The host (CXX) build of this runner is only used by the internal
+        # fbcode buck-native x86 QNN simulator test. Keep it out of OSS builds
+        # (CXX there includes macOS, which has no QNN host libs) -- restore the
+        # original Android-only surface in OSS.
+        platforms = [ANDROID, CXX] if is_fbcode() else [ANDROID],
         external_deps = [
             "gflags",
         ],