James Charles Dahlman (December 15, 1856 – January 21, 1930), also known as Jim Dahlman, Cowboy Jim and Mayor Jim, was elected to eight terms as mayor of Omaha, Nebraska, serving the city for 20 years over a 23-year-period. A German-American and an agnostic, Dahlman grew up in a ranching area and started working as a Texas cowboy. He was elected as a county sheriff and small town mayor in western Nebraska before moving to Omaha.