Born in Eveleth, Minnesota, Brimsek was one of the first great American hockey players. In the 1938–39 season, he was promoted to the Bruins following an injury to goaltender Tiny Thompson. He notched 10 shutouts that season, earning him the nickname "Mr. Zero." He won the Calder Memorial Trophy as NHL Rookie of the Year, and helped the Bruins win the Stanley Cup in 1938-39, and again in 1940-41.

In 1943, the Second World War interrupted Brimsek's career, and he joined the Coast Guard. He played on the Coast Guard "Cutters" hockey team and then served aboard a Coast Guard supply ship in the Pacific until the end of the war.[1]

He resumed his career with the Bruins in 1945-46 and played with them until 1948-49, when he was sold to the Chicago Black Hawks where he played his final year in the NHL.[2] He was inducted into the Hockey Hall of Fame in 1966 (the first American to earn HHOF membership) and was inducted into the United States Hockey Hall of Fame in 1973. In 1998, shortly before his death, he was ranked number 67 on The Hockey News' list of the 100 Greatest Hockey Players.

Despite the success of Thompson and Brimsek, both of whom were elected to the Hall of Fame and wore uniform number 1, the Bruins are the only one of the NHL's "Original Six" teams not to have retired the number (or, in the case of the Toronto Maple Leafs, hung banners indicating it is an "Honoured Number" while leaving it in circulation).

An annual award given to the top high school goaltender in the state of Minnesota is given in Brimsek's honor. Brimsek, who won 252 games, held the record for winningest American-born netminder until Tom Barrasso of the Pittsburgh Penguins broke his long-held record on February 15, 1994 by beating the Winnipeg Jets.