diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
index 0608ac3fd83be..3e83b8d5bdad7 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
@@ -1490,12 +1490,14 @@ def __init__(
         init_commands: list[str] = [],
         log_file: Optional[TextIO] = None,
         env: Optional[dict[str, str]] = None,
+        additional_args: list[str] = [],
     ):
         self.process = None
         self.connection = None
         if executable is not None:
             process, connection = DebugAdapterServer.launch(
-                executable=executable, connection=connection, env=env, log_file=log_file
+                executable=executable, connection=connection, env=env, log_file=log_file,
+                additional_args=additional_args
             )
             self.process = process
             self.connection = connection
@@ -1528,6 +1530,7 @@ def launch(
         env: Optional[dict[str, str]] = None,
         log_file: Optional[TextIO] = None,
         connection: Optional[str] = None,
+        additional_args: list[str] = [],
     ) -> tuple[subprocess.Popen, Optional[str]]:
         adapter_env = os.environ.copy()
         if env is not None:
@@ -1537,6 +1540,9 @@ def launch(
             adapter_env["LLDBDAP_LOG"] = log_file
         args = [executable]
 
+        # Add additional arguments first (like --no-lldbinit)
+        args.extend(additional_args)
+
         if connection is not None:
             args.append("--connection")
             args.append(connection)
diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/lldbdap_testcase.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/lldbdap_testcase.py
index b28a78792c70f..fffd4c23d6fcd 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/lldbdap_testcase.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/lldbdap_testcase.py
@@ -21,6 +21,7 @@ def create_debug_adapter(
         self,
         lldbDAPEnv: Optional[dict[str, str]] = None,
         connection: Optional[str] = None,
+        additional_args: Optional[list[str]] = None,
     ):
         """Create the Visual Studio Code debug adapter"""
         self.assertTrue(
@@ -33,15 +34,17 @@ def create_debug_adapter(
             init_commands=self.setUpCommands(),
             log_file=log_file_path,
             env=lldbDAPEnv,
+            additional_args=additional_args or [],
         )
 
     def build_and_create_debug_adapter(
         self,
         lldbDAPEnv: Optional[dict[str, str]] = None,
         dictionary: Optional[dict] = None,
+        additional_args: Optional[list[str]] = None,
     ):
         self.build(dictionary=dictionary)
-        self.create_debug_adapter(lldbDAPEnv)
+        self.create_debug_adapter(lldbDAPEnv, additional_args=additional_args)
 
     def build_and_create_debug_adapter_for_attach(self):
         """Variant of build_and_create_debug_adapter that builds a uniquely
diff --git a/lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py b/lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py
index 41112a4f5b9e3..4b384e260ad24 100644
--- a/lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py
+++ b/lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py
@@ -7,6 +7,7 @@
 import lldbdap_testcase
 import os
 import re
+import tempfile
 
 # Many tests are skipped on Windows because get_stdout() returns None there.
 # Despite the test program printing correctly. See
@@ -582,3 +583,46 @@ def test_version(self):
             version_string.splitlines(),
             "version string does not match",
         )
+
+    def test_no_lldbinit_flag(self):
+        """
+        Test that the --no-lldbinit flag prevents sourcing .lldbinit files.
+        """
+        # Create a temporary .lldbinit file in the home directory
+        with tempfile.TemporaryDirectory() as temp_home:
+            lldbinit_path = os.path.join(temp_home, ".lldbinit")
+
+            # Write a command to the .lldbinit file that would set a unique setting
+            with open(lldbinit_path, "w") as f:
+                f.write("settings set stop-disassembly-display never\n")
+                f.write("settings set target.x86-disassembly-flavor intel\n")
+
+            # Test with --no-lldbinit flag (should NOT source .lldbinit)
+            self.build_and_create_debug_adapter(
+                lldbDAPEnv={"HOME": temp_home},
+                additional_args=["--no-lldbinit"]
+            )
+            program = self.getBuildArtifact("a.out")
+
+            # Use initCommands to check if .lldbinit was sourced
+            initCommands = ["settings show stop-disassembly-display"]
+
+            # Initialize the DAP session (should NOT source .lldbinit due to --no-lldbinit)
+            self.dap_server.request_initialize()
+
+            # Launch with initCommands to check the setting
+            self.launch(program, initCommands=initCommands, stopOnEntry=True)
+
+            # Get console output to verify the setting was NOT set from .lldbinit
+            output = self.get_console()
+            self.assertTrue(output and len(output) > 0, "expect console output")
+
+            # Verify the setting has default value, not "never" from .lldbinit
+            self.assertNotIn(
+                "never",
+                output,
+                "Setting should have default value when --no-lldbinit is used",
+            )
+
+            # Verify the initCommands were executed
+            self.verify_commands("initCommands", output, initCommands)
diff --git a/lldb/tools/lldb-dap/DAP.cpp b/lldb/tools/lldb-dap/DAP.cpp
index b1ad38d983893..9c1966ea4238a 100644
--- a/lldb/tools/lldb-dap/DAP.cpp
+++ b/lldb/tools/lldb-dap/DAP.cpp
@@ -121,12 +121,13 @@ static std::string capitalize(llvm::StringRef str) {
 llvm::StringRef DAP::debug_adapter_path = "";
 
 DAP::DAP(Log *log, const ReplMode default_repl_mode,
-         std::vector<std::string> pre_init_commands,
+         std::vector<std::string> pre_init_commands, bool no_lldbinit,
          llvm::StringRef client_name, DAPTransport &transport, MainLoop &loop)
     : log(log), transport(transport), broadcaster("lldb-dap"),
       progress_event_reporter(
           [&](const ProgressEvent &event) { SendJSON(event.ToJSON()); }),
-      repl_mode(default_repl_mode), m_client_name(client_name), m_loop(loop) {
+      repl_mode(default_repl_mode), no_lldbinit(no_lldbinit),
+      m_client_name(client_name), m_loop(loop) {
   configuration.preInitCommands = std::move(pre_init_commands);
   RegisterRequests();
 }
diff --git a/lldb/tools/lldb-dap/DAP.h b/lldb/tools/lldb-dap/DAP.h
index 04f70f76a09cd..71681fd4b51ed 100644
--- a/lldb/tools/lldb-dap/DAP.h
+++ b/lldb/tools/lldb-dap/DAP.h
@@ -156,6 +156,9 @@ struct DAP final : private DAPTransport::MessageHandler {
   /// The set of features supported by the connected client.
   llvm::DenseSet<ClientFeature> clientFeatures;
 
+  /// Whether to disable sourcing .lldbinit files.
+  bool no_lldbinit;
+
   /// The initial thread list upon attaching.
   std::vector<protocol::Thread> initial_thread_list;
 
@@ -178,13 +181,16 @@ struct DAP final : private DAPTransport::MessageHandler {
   /// \param[in] pre_init_commands
   ///     LLDB commands to execute as soon as the debugger instance is
   ///     allocated.
+  /// \param[in] no_lldbinit
+  ///     Whether to disable sourcing .lldbinit files.
   /// \param[in] transport
   ///     Transport for this debug session.
   /// \param[in] loop
   ///     Main loop associated with this instance.
   DAP(Log *log, const ReplMode default_repl_mode,
-      std::vector<std::string> pre_init_commands, llvm::StringRef client_name,
-      DAPTransport &transport, lldb_private::MainLoop &loop);
+      std::vector<std::string> pre_init_commands, bool no_lldbinit,
+      llvm::StringRef client_name, DAPTransport &transport,
+      lldb_private::MainLoop &loop);
 
   ~DAP();
 
diff --git a/lldb/tools/lldb-dap/Handler/InitializeRequestHandler.cpp b/lldb/tools/lldb-dap/Handler/InitializeRequestHandler.cpp
index b499a69876e2c..9069de4a3a690 100644
--- a/lldb/tools/lldb-dap/Handler/InitializeRequestHandler.cpp
+++ b/lldb/tools/lldb-dap/Handler/InitializeRequestHandler.cpp
@@ -42,8 +42,11 @@ llvm::Expected<InitializeResponse> InitializeRequestHandler::Run(
 
   // The sourceInitFile option is not part of the DAP specification. It is an
   // extension used by the test suite to prevent sourcing `.lldbinit` and
-  // changing its behavior.
-  if (arguments.lldbExtSourceInitFile.value_or(true)) {
+  // changing its behavior. The CLI flag --no-lldbinit takes precedence over
+  // the DAP parameter.
+  bool should_source_init_files =
+      !dap.no_lldbinit && arguments.lldbExtSourceInitFile.value_or(true);
+  if (should_source_init_files) {
     dap.debugger.SkipLLDBInitFiles(false);
     dap.debugger.SkipAppInitFiles(false);
     lldb::SBCommandReturnObject init;
diff --git a/lldb/tools/lldb-dap/Options.td b/lldb/tools/lldb-dap/Options.td
index 867753e9294a6..b3fb592c84a8e 100644
--- a/lldb/tools/lldb-dap/Options.td
+++ b/lldb/tools/lldb-dap/Options.td
@@ -61,3 +61,9 @@ def pre_init_command: S<"pre-init-command">,
 def: Separate<["-"], "c">,
   Alias<pre_init_command>,
   HelpText<"Alias for --pre-init-command">;
+
+def no_lldbinit: F<"no-lldbinit">,
+  HelpText<"Do not automatically parse any '.lldbinit' files.">;
+def: Flag<["-"], "x">,
+  Alias<no_lldbinit>,
+  HelpText<"Alias for --no-lldbinit">;
diff --git a/lldb/tools/lldb-dap/tool/lldb-dap.cpp b/lldb/tools/lldb-dap/tool/lldb-dap.cpp
index b74085f25f4e2..2431cf8fb2f24 100644
--- a/lldb/tools/lldb-dap/tool/lldb-dap.cpp
+++ b/lldb/tools/lldb-dap/tool/lldb-dap.cpp
@@ -258,7 +258,8 @@ validateConnection(llvm::StringRef conn) {
 static llvm::Error
 serveConnection(const Socket::SocketProtocol &protocol, const std::string &name,
                 Log *log, const ReplMode default_repl_mode,
-                const std::vector<std::string> &pre_init_commands) {
+                const std::vector<std::string> &pre_init_commands,
+                bool no_lldbinit) {
   Status status;
   static std::unique_ptr<Socket> listener = Socket::Create(protocol, status);
   if (status.Fail()) {
@@ -303,8 +304,8 @@ serveConnection(const Socket::SocketProtocol &protocol, const std::string &name,
       llvm::set_thread_name(client_name + ".runloop");
       MainLoop loop;
       Transport transport(client_name, log, io, io);
-      DAP dap(log, default_repl_mode, pre_init_commands, client_name, transport,
-              loop);
+      DAP dap(log, default_repl_mode, pre_init_commands, no_lldbinit,
+              client_name, transport, loop);
 
       if (auto Err = dap.ConfigureIO()) {
         llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(),
@@ -508,6 +509,8 @@ int main(int argc, char *argv[]) {
     pre_init_commands.push_back(arg);
   }
 
+  bool no_lldbinit = input_args.hasArg(OPT_no_lldbinit);
+
   if (!connection.empty()) {
     auto maybeProtoclAndName = validateConnection(connection);
     if (auto Err = maybeProtoclAndName.takeError()) {
@@ -520,7 +523,7 @@ int main(int argc, char *argv[]) {
     std::string name;
     std::tie(protocol, name) = *maybeProtoclAndName;
     if (auto Err = serveConnection(protocol, name, log.get(), default_repl_mode,
-                                   pre_init_commands)) {
+                                   pre_init_commands, no_lldbinit)) {
       llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(),
                                   "Connection failed: ");
       return EXIT_FAILURE;
@@ -556,8 +559,8 @@ int main(int argc, char *argv[]) {
   constexpr llvm::StringLiteral client_name = "stdio";
   MainLoop loop;
   Transport transport(client_name, log.get(), input, output);
-  DAP dap(log.get(), default_repl_mode, pre_init_commands, client_name,
-          transport, loop);
+  DAP dap(log.get(), default_repl_mode, pre_init_commands, no_lldbinit,
+          client_name, transport, loop);
 
   // stdout/stderr redirection to the IDE's console
   if (auto Err = dap.ConfigureIO(stdout, stderr)) {
diff --git a/lldb/unittests/DAP/DAPTest.cpp b/lldb/unittests/DAP/DAPTest.cpp
index d5a9591ad0a43..2090fe6896d6b 100644
--- a/lldb/unittests/DAP/DAPTest.cpp
+++ b/lldb/unittests/DAP/DAPTest.cpp
@@ -28,6 +28,7 @@ TEST_F(DAPTest, SendProtocolMessages) {
       /*log=*/nullptr,
       /*default_repl_mode=*/ReplMode::Auto,
       /*pre_init_commands=*/{},
+      /*no_lldbinit=*/false,
       /*client_name=*/"test_client",
       /*transport=*/*transport,
       /*loop=*/loop,
diff --git a/lldb/unittests/DAP/TestBase.cpp b/lldb/unittests/DAP/TestBase.cpp
index 54ac27da694e6..ba7baf2103799 100644
--- a/lldb/unittests/DAP/TestBase.cpp
+++ b/lldb/unittests/DAP/TestBase.cpp
@@ -55,6 +55,7 @@ void DAPTestBase::SetUp() {
       /*log=*/log.get(),
       /*default_repl_mode=*/ReplMode::Auto,
       /*pre_init_commands=*/std::vector<std::string>(),
+      /*no_lldbinit=*/false,
       /*client_name=*/"test_client",
       /*transport=*/*transport, /*loop=*/loop);
 }