The 1921 Idaho Vandals football team represented the University of Idaho as a member of the Northwest Conference during the 1921 college football season. Led by Thomas Kelley in his second and final season as head coach, the Vandals compiled an overall record of 4âÂÂ3âÂÂ1 with a mark of 1âÂÂ2âÂÂ1 in conference play, placing fifth in the Northwest Conference. The Vandals had two home games in Moscow, one on campus at MacLean Field and another at the fairgrounds; they also played one in Boise at Public School Field.
Idaho dropped a seventh consecutive game to Washington State in the Battle of the Palouse, falling at Rogers Field Two years later, the Vandals won the first of three consecutive, their only three-peat in the rivalry series. The Boise game against Wyoming on the third anniversary of Armistice Day was attended by Governor
The following June, Kelley left for the University of Missouri and was succeeded at Idaho by Robert L. Mathews.