William A. Carter (1818-1881) was a businessman and judge at Fort Bridger, Wyoming.

William Alexander Carter was born to Lucinda Washington Alexander and John Wormeley Carter on April 15, 1818 in Prince William County, Virginia. Around 1857 to 1858 William A. Carter came with Johnston's Army as a sutler, or storekeeper, to Fort Bridger, Wyoming. Carter and his wife, Mary Eliza Hamilton, had six children: Ada, Anna, Lulie, Roberta, William A. and Edgar. He stayed at Fort Bridger with his family rebuilding and restocking the fort. One of the region's early businessmen, Carter was involved in mining, oil, logging, and cattle ranching, and he also operated a sawmill. He raised hay and grain on the land surrounding the Fort to fill contracts with the government. Carter was soon known as Mr. Fort Bridger, and became Wyoming's first millionaire. In addition to his business activities Carter was justice of the peace and probate judge for Green River County.