Bầu cử Thượng viện Hoa Kỳ tại Maine năm 1976

The 1976 United States Senate election in Maine took place on November 2, 1976. Incumbent Democratic senator Edmund Muskie won re-election to a fourth term, defeating Republican nominee Robert Monks by 99,215 votes. Muskie carried 15 of Maine's 16 counties, with Monks winning only Hancock County.

This would be Muskie's final election. He would resign to become Secretary of State in 1980. George J. Mitchell, a fellow Democrat, would be nominated by Governor Joseph E. Brennan to take the seat following Muskie's resignation. Monks, who had unsuccessfully challenged incumbent senator Margaret Chase Smith in the Republican primary four years earlier, would go on to become chairman of the Maine Republican Party from 1977 to 1978, and hold several positions in the federal government under president Ronald Reagan. He would make a third run for the U.S. Senate in 1996, losing the Republican primary to Susan Collins. Though Monks remained a registered Republican until his death, he would endorse Democratic president Barack Obama's re-election campaign in 2012.