Zales Nelson Ecton (April 1, 1898 – March 3, 1961) was a rare Republican United States senator from Montana, having served from 1947 to 1953.
Ecton was born in Weldon, Decatur County, Iowa. He moved with his family to Gallatin County, Montana, when he was nine years old. He attended the Gallatin County public schools, the then Montana State College (later Montana State University) at Bozeman and the University of Chicago law school. In 1921, he became a rancher and gained interests in grain and livestock.
Entering politics, he was a member of the Montana state House from 1933 to 1937 and the Montana state senate from 1937 to 1946. In 1946, he ran for the Montana United States Senate seat which was being vacated by Democrat Burton K. Wheeler, who had lost the Democratic primary.
As part of the Republican takeover of the Senate in 1946, Ecton defeated Democratic state Supreme Court Justice Leif Erickson by a vote of 54% to 46%. He served in the Senate for one term, having been narrowly defeated for reelection in 1952 by U.S. Representative Mike Mansfield, a Democratic college professor and Far Eastern expert. Ecton resumed his ranching business and died in Bozeman.
Ecton was the last Republican U.S. senator from Montana until the election in 1988 of Conrad Burns, who served from 1989 to 2007.