In 1825, Michael Milton and his wife, Martha Clark, along with several slaves, blazed a trail from the Amite River near Benton Ferry Landing and founded Walker. The resulting village that grew up was first named Milton Old Field. A post office was first established in the area in 1856 and named in honor of Dr. William E. Walker of Springfield, a state legislator respresenting the area. He died of disease during the Civil War while serving as an officer in the Confederate States Army.
The post office was discontinued in 1860, then reopened in 1876 – first as Milton Old Field then Ralley Hill Post Office. It was finally renamed Walker in 1890. The Town of Walker was incorporated in 1909, and its corporate limits now include the former incorporated village of Corbin, which was annexed in 1971 after a municipal merger election. Walker unofficially became a city in 2002, when its population first exceeded 5,000. The change became official when Gov. Bobby Jindal formally proclaimed Walker a city with a Proclamation dated June 24, 2011 stating the new population of Walker to be 6,138.