diff --git a/daml-assistant/daml-helper/src/DA/Daml/Helper/Main.hs b/daml-assistant/daml-helper/src/DA/Daml/Helper/Main.hs
index 42e9619d9482..cc3e1373f8e4 100644
--- a/daml-assistant/daml-helper/src/DA/Daml/Helper/Main.hs
+++ b/daml-assistant/daml-helper/src/DA/Daml/Helper/Main.hs
@@ -44,6 +44,9 @@ data Command
       , jsonApiCfg :: JsonApiConfig
       , onStartM :: Maybe String
       , waitForSignal :: WaitForSignal
+      , sandboxOptions :: SandboxOptions
+      , navigatorOptions :: NavigatorOptions
+      , jsonApiOptions :: JsonApiOptions
       }
     | Deploy { flags :: HostAndPortFlags }
     | LedgerListParties { flags :: HostAndPortFlags, json :: JsonFlag }
@@ -106,6 +109,9 @@ commandParser = subparser $ fold
         <*> jsonApiCfg
         <*> optional (option str (long "on-start" <> metavar "COMMAND" <> help "Command to run once sandbox and navigator are running."))
         <*> (WaitForSignal <$> flagYesNoAuto "wait-for-signal" True "Wait for Ctrl+C or interrupt after starting servers." idm)
+        <*> (SandboxOptions <$> many (strOption (long "sandbox-option" <> metavar "SANDBOX_OPTION" <> help "Pass option to sandbox")))
+        <*> (NavigatorOptions <$> many (strOption (long "navigator-option" <> metavar "NAVIGATOR_OPTION" <> help "Pass option to navigator")))
+        <*> (JsonApiOptions <$> many (strOption (long "json-api-option" <> metavar "JSON_API_OPTION" <> help "Pass option to HTTP JSON API")))
 
     deployCmdInfo = mconcat
         [ progDesc $ concat
@@ -215,7 +221,17 @@ runCommand New {..} = runNew targetFolder templateNameM []
 runCommand Migrate {..} = runMigrate targetFolder pkgPathFrom pkgPathTo
 runCommand Init {..} = runInit targetFolderM
 runCommand ListTemplates = runListTemplates
-runCommand Start {..} = runStart sandboxPortM startNavigator jsonApiCfg openBrowser onStartM waitForSignal
+runCommand Start {..} =
+    runStart
+        sandboxPortM
+        startNavigator
+        jsonApiCfg
+        openBrowser
+        onStartM
+        waitForSignal
+        sandboxOptions
+        navigatorOptions
+        jsonApiOptions
 runCommand Deploy {..} = runDeploy flags
 runCommand LedgerListParties {..} = runLedgerListParties flags json
 runCommand LedgerAllocateParties {..} = runLedgerAllocateParties flags parties
diff --git a/daml-assistant/daml-helper/src/DA/Daml/Helper/Run.hs b/daml-assistant/daml-helper/src/DA/Daml/Helper/Run.hs
index e850f49ef750..1a412ccf573e 100644
--- a/daml-assistant/daml-helper/src/DA/Daml/Helper/Run.hs
+++ b/daml-assistant/daml-helper/src/DA/Daml/Helper/Run.hs
@@ -35,6 +35,9 @@ module DA.Daml.Helper.Run
     , StartNavigator(..)
     , WaitForSignal(..)
     , DamlHelperError(..)
+    , SandboxOptions(..)
+    , NavigatorOptions(..)
+    , JsonApiOptions(..)
     ) where
 
 import Control.Concurrent
@@ -728,8 +731,32 @@ data JsonApiConfig = JsonApiConfig
 -- | Whether `daml start` should wait for Ctrl+C or interrupt after starting servers.
 newtype WaitForSignal = WaitForSignal Bool
 
-runStart :: Maybe SandboxPort -> StartNavigator -> JsonApiConfig -> OpenBrowser -> Maybe String -> WaitForSignal -> IO ()
-runStart sandboxPortM (StartNavigator shouldStartNavigator) (JsonApiConfig mbJsonApiPort) (OpenBrowser shouldOpenBrowser) onStartM (WaitForSignal shouldWaitForSignal) = withProjectRoot Nothing (ProjectCheck "daml start" True) $ \_ _ -> do
+newtype SandboxOptions = SandboxOptions [String]
+newtype NavigatorOptions = NavigatorOptions [String]
+newtype JsonApiOptions = JsonApiOptions [String]
+
+runStart
+    :: Maybe SandboxPort
+    -> StartNavigator
+    -> JsonApiConfig
+    -> OpenBrowser
+    -> Maybe String
+    -> WaitForSignal
+    -> SandboxOptions
+    -> NavigatorOptions
+    -> JsonApiOptions
+    -> IO ()
+runStart
+  sandboxPortM
+  (StartNavigator shouldStartNavigator)
+  (JsonApiConfig mbJsonApiPort)
+  (OpenBrowser shouldOpenBrowser)
+  onStartM
+  (WaitForSignal shouldWaitForSignal)
+  (SandboxOptions sandboxOpts)
+  (NavigatorOptions navigatorOpts)
+  (JsonApiOptions jsonApiOpts)
+  = withProjectRoot Nothing (ProjectCheck "daml start" True) $ \_ _ -> do
     let sandboxPort = fromMaybe defaultSandboxPort sandboxPortM
     projectConfig <- getProjectConfig
     darPath <- getDarPath
@@ -738,12 +765,12 @@ runStart sandboxPortM (StartNavigator shouldStartNavigator) (JsonApiConfig mbJso
         queryProjectConfig ["scenario"] projectConfig
     doBuild
     let scenarioArgs = maybe [] (\scenario -> ["--scenario", scenario]) mbScenario
-    withSandbox sandboxPort (darPath : scenarioArgs) $ \sandboxPh -> do
-        withNavigator' sandboxPh sandboxPort navigatorPort [] $ \navigatorPh -> do
+    withSandbox sandboxPort (darPath : scenarioArgs ++ sandboxOpts) $ \sandboxPh -> do
+        withNavigator' sandboxPh sandboxPort navigatorPort navigatorOpts $ \navigatorPh -> do
             whenJust onStartM $ \onStart -> runProcess_ (shell onStart)
             when (shouldStartNavigator && shouldOpenBrowser) $
                 void $ openBrowser (navigatorURL navigatorPort)
-            withJsonApi' sandboxPh sandboxPort [] $ \jsonApiPh -> do
+            withJsonApi' sandboxPh sandboxPort jsonApiOpts $ \jsonApiPh -> do
                 when shouldWaitForSignal $
                   void $ waitAnyCancel =<< mapM (async . waitExitCode) [navigatorPh,sandboxPh,jsonApiPh]
 
diff --git a/docs/source/tools/assistant.rst b/docs/source/tools/assistant.rst
index 0a768b65f127..21224c4f4cb8 100644
--- a/docs/source/tools/assistant.rst
+++ b/docs/source/tools/assistant.rst
@@ -19,6 +19,8 @@ DAML Assistant (``daml``)
   - Launch :doc:`DAML Studio </daml/daml-studio>`: ``daml studio``
   - Launch :doc:`Sandbox </tools/sandbox>`, :doc:`Navigator </tools/navigator/index>` and the HTTP JSON API: ``daml start``
     You can disable the HTTP JSON API by passing ``--json-api-port none`` to ``daml start``.
+    To specify additional options for sandbox/navigator/the HTTP JSON API you can use
+    ``--sandbox-option=opt``, ``--navigator-option=opt`` and ``--json-api-option=opt``.
   - Launch Sandbox: ``daml sandbox``
   - Launch Navigator: ``daml navigator``
   - Launch :doc:`Extractor </tools/extractor>`: ``daml extractor``
diff --git a/unreleased.rst b/unreleased.rst
index dc9609937dd1..5814c85e45d2 100644
--- a/unreleased.rst
+++ b/unreleased.rst
@@ -9,3 +9,6 @@ This page contains release notes for the SDK.
 HEAD — ongoing
 --------------
 
+- [DAML Assistant] ``daml start`` now supports ``--sandbox-option=opt``, ``--navigator-option=opt``
+  and ``--json-api-option=opt`` to pass additional option to sandbox/navigator/json-api.
+  These flags can be specified multiple times.