Sultana Steamboat Disaster Commemorative Coin Act of 2021 This bill directs the Department of the Treasury to mint and issue $5 gold coins, $1 silver coins, and half-dollar clad coins in recognition and remembrance of the Sultana Steamboat explosion of 1865. The designs of the coins shall be emblematic of the historical significance of the Sultana disaster, with special recognition and remembrance given to the lives lost, including the recently released Union soldiers returning home after having been prisoners of war during the American Civil War at Confederate prisons located at Andersonville and Cahaba. Treasury may issue coins minted under this bill to the public only during the one-year period beginning on January 1, 2023. All sales of such coins shall include a surcharge to be paid to the Sultana Historical Preservation Society, Inc. to establish and maintain a new Sultana disaster museum.