Empire Bittern was a steamship, built as a livestock-carrying cargo ship in 1902 at Belfast, Ireland as Iowa for the Ltd of Liverpool. The ship was sold to the Hamburg Amerika Linie and renamed Bohemia in 1913. With the World War II emergency in shipping the ship was transferred to the Ministry of War Transport (MoWT) in 1941, becoming one of the Empire ships, Empire Bittern. The ship was operated for MoWT by Royal Mail Lines Ltd. and made several Atlantic crossings in convoy. In July 1944 Empire Bittern was sunk as a blockship in support of Operation Overlord.