Admitted to the State Bar of Texas in 1971 after earning his law degree at Southern Methodist University, Todd first practiced with a Galveston insurance defense firm, later joining the law firm of Wellborn, Britt and Brown in Alvin, Texas. It was during his 25-year personal injury practice in Alvin that The Law Firm of Alton C. Todd was formed, which moved to Friendswood in 2000.