Adam McMullen (June 12, 1872 – March 2, 1959) was an American Republican politician and was the 21st Governor of Nebraska.

McMullen was born in Wellsville, New York and as a young boy moved with his family to Wymore, Nebraska.

[1] Still in Washington, D. C. after his graduation in 1899, McMullen worked as a secretary for Nebraska Congressman Jesse Strode, then for Senator Charles Henry Dietrich.

He returned to Wymore, Nebraska where he passed the state bar and entered into private practice.

After stepping down from governorship, McMullen settled in Beatrice, Nebraska and continued to stay politically active while pursuing his own business interests.