USS S-42, first of a class of six 1126-ton submarines built at Quincy, Massachusetts, was commissioned in November 1924. She mainly served in the Panama area for the next few years and after 1927 operated along the West Coast and in Hawaiian waters, with occasional moves back to Panama and the Caribbean to participate in U.S. Fleet exercises. From 1936 into 1941, S-42 was again based at Coco Solo, Panama Canal Zone.

Following modernization work and brief service out of Bermuda, S-42 returned to the Panama area, where she remained until early 1942. After transfer to Australian waters, she began combat operations in late April 1942. Patrolling off New Ireland, on 11 May S-42 sank the Japanese minelayer Okinoshima and was damaged when the enemy counter-attacked with depth charges. During the submarine's second war patrol, in July 1942, she landed an Australian intelligence officer on New Britain. Her next two patrols were made in the Solomon Islands area during August-November, in support of the ongoing Guadalcanal campaign.

S-42 came back to the the United States later in 1942 and spent the next several months in overhaul and training. She served in the Aleutians from August 1943 until February 1944, but mechanical problems ensured that she completed only one war patrol. The elderly submarine was then sent to the southwest Pacific, where she operated in the New Guinea and Admiralties areas. Though primarily assigned to support anti-submarine warfare training, S-42 was employed to land an intelligence party on Halmahera Island in August 1944. Thereafter, she continued her ASW training service in the Admiralties until February 1945, when she moved to San Diego, California, to take up similar duties. USS S-42 was decommissioned in October 1945, several weeks after the end of the Pacific War, and was sold for scrapping in November 1946.