USS Walrus (SS-431), a proposed United States Navy Balao-class submarine, was the second ship of the United States Navy to be named for the walrus. Her construction by the Cramp Shipbuilding Company in Philadelphia, Pennsylvania, was authorized but the contract for her construction was cancelled on 29 July 1944.
The name USS Walrus was used for a fictional U.S. Navy submarine in Edward L. Beach's 1955 novel Run Silent, Run Deep.