I-55 was a Japanese C3 class attack submarine completed on 20 April 1944. Assigned to the defense of the Marianas, during a mission to rescue staff of the 1st Air Fleet on Tinian, she was presumably found and sunk by the USS Gilmer and USS William C. Miller on 14 July 1944, though some sources claim this sinking was actually the Ro-48. See also USS Wyman and USS Reynolds references to the sinking of this submarine in which Wyman claims credit for this sinking on 28 July 1944.