1966 United States Senate election in Oregon

1966 United States Senate election in Oregon
	County results ; Hatfield: 50-60% 60-70% 70-80% Duncan: 50–60%
U.S. senator before election; Maurine Neuberger; Democratic	Elected U.S. Senator ; Mark Hatfield; Republican

The 1966 Oregon United States Senate election was held on November 6, 1966 to select the U.S. Senator from the state of Oregon. Incumbent Senator Maurine Brown Neuberger did not seek re-election. Held during the escalation of United States involvement of the Vietnam War, the race was between Republican candidate and incumbent Governor of Oregon Mark Hatfield, who opposed the war, and Democratic congressman Robert B. Duncan, who supported the war. In an unusual move, Oregon's other Senator, Democrat Wayne Morse, who also opposed the war, crossed party lines to endorse Hatfield, who won in a close election, his first of five terms in the United States Senate.