Seaton was born in Washington, D.C., on December 11, 1909, the son of Dorothea Elizabeth (née Schmidt) and Fay Noble Seaton. He attended the Manhattan High School in Manhattan, Kansas. He graduated from Kansas State University in 1931, and married Gladys Hope Dowd (November 5, 1910 – January 5, 1999) in the same year. They had four children: Donald Richard, Alfred Noble, Johanna Christine, and Monica Margaret Seaton. In 1937, Seaton moved to Hastings, Nebraska, where he was for many years the publisher of the Hastings Tribune.
Seaton served in various White House and subcabinet posts in Eisenhower's administration, including Assistant Secretary of Defense for Legislative Affairs, before he was appointed as the U.S. Secretary of the Interior. He served in that office from June 8, 1956, until January 20, 1961. During his tenure, Alaska and Hawaii became the 49th and 50th states admitted to the Union. He was instrumental in the passing of the Alaska Statehood Act, appointing and recommending pro-Alaska politicians to high positions, such as Ted Stevens to Senior Counsel to the Secretary of Interior (later becoming Solicitor in 1960) and Mike Stepovich to Governor of the Territory of Alaska.