McMahan is a surname. Notable people with the surname include:
Alan McMahan, Christian theologian
Brian McMahan, American guitarist
Chad McMahan, American politician.
Jack McMahan (born 1932), American baseball player
Jeff McMahan, American philosopher
Jeff McMahan, American politician
Kevin McMahan (born 1983), American football player
Mickey McMahan (1930–2008), American trumpeter
Ronnie McMahan (born 1972), American basketball player
W. Edwin McMahan, American politician