William J. Keeler (fl. c. 1859 - 1869) was an American civil engineer employed with the U.S. Government's Indian Bureau during the second half of the 19th century. He produced one great map, his National Map of The Territory of The United States from the Mississippi River to the Pacific Ocean, which is one of the most important maps of the American west to appear in the 19th century. Otherwise, little is known of his life.