diff --git a/main/actor.hs b/main/actor.hs
--- a/main/actor.hs
+++ b/main/actor.hs
@@ -14,6 +14,8 @@
 data Args = Args
   { config  :: FilePath
     -- ^ Configuration file.
+  , quiesce :: Maybe FilePath
+    -- ^ Optional quiesce file to stop actor.
   , queue   :: Text
     -- ^ Queue to listen to act on.
   , num     :: Maybe Int
@@ -35,6 +37,7 @@
   args <- getRecord "Actor"
   actMain
     (config args)
+    (quiesce args)
     (queue args)
     (fromMaybe 1 $ num args)
     (nocopy args)
diff --git a/src/Network/AWS/Wolf/Act.hs b/src/Network/AWS/Wolf/Act.hs
--- a/src/Network/AWS/Wolf/Act.hs
+++ b/src/Network/AWS/Wolf/Act.hs
@@ -16,6 +16,7 @@
 import Network.AWS.Wolf.Prelude
 import Network.AWS.Wolf.SWF
 import Network.AWS.Wolf.Types
+import System.Directory
 import System.Process
 
 -- | S3 copy call.
@@ -63,6 +64,11 @@
     traceInfo "end" [ "exception" .= (displayException <$> e) ]
     pure e
 
+-- | Check if quiesce file is present.
+--
+check :: MonadIO m => Maybe FilePath -> m Bool
+check = maybe (pure False) (liftIO . doesFileExist)
+
 -- | Actor logic - poll for work, download artifacts, run command, upload artifacts.
 --
 act :: MonadConf c m => Text -> Bool -> Bool -> String -> m ()
@@ -102,10 +108,12 @@
 
 -- | Run actor from main with config file.
 --
-actMain :: MonadControl m => FilePath -> Text -> Int -> Bool -> Bool -> String -> m ()
-actMain cf queue num nocopy local command =
+actMain :: MonadControl m => FilePath -> Maybe FilePath -> Text -> Int -> Bool -> Bool -> String -> m ()
+actMain cf quiesce queue num nocopy local command =
   runCtx $
     runStatsCtx $ do
       conf <- readYaml cf
       runConfCtx conf $
-        runConcurrent $ replicate num $ forever $ act queue nocopy local command
+        runConcurrent $ replicate num $ forever $ do
+          boolThrowIO "Quiesce" =<< not <$> check quiesce
+          act queue nocopy local command
diff --git a/wolf.cabal b/wolf.cabal
--- a/wolf.cabal
+++ b/wolf.cabal
@@ -1,5 +1,5 @@
 name:                  wolf
-version:               0.3.27
+version:               0.3.28
 synopsis:              Amazon Simple Workflow Service Wrapper.
 description:           Wolf is a wrapper around Amazon Simple Workflow Service.
 homepage:              https://github.com/swift-nav/wolf