Belfour began his career with the Chicago Blackhawks.

Born April 21, 1965 in Carman, Manitoba, Belfour was still playing Tier Two hockey for the Winkler Flyers of the Manitoba Junior League as an overage player back in 1985-86 when he was 21. From there, Belfour accepted a scholarship to the University of North Dakota, where he first began to show signs that he had the potential of being a top-flight goaltender. He won 29 of 34 games and caught the attention of the Chicago Blackhawks scouting staff.

Belfour won the Vezina Trophy on two occasions and the William M. Jennings Trophy four times.

Belfour ranks third on the NHL's All-Time Win Leaders list with 484.

The Belfour days in Chicago came to a surprising end in January 1997 when he was dealt to the San Jose Sharks when it became apparent the two sides were not going to be able to work out a new contract. He remained with the Sharks for the duration of the 1996-97 season before signing a free-agent deal with the Dallas Stars. Belfour played in the Lone Star State for five years, and led the organization to its first Stanley Cup title in 1999, beating the Buffalo Sabres in the finals. Belfour remained the Stars' number one netminder through the 2001-02 season, but a dismal year for the team and a record of 21-27-11 record for Belfour left the Stars out of the playoffs and it was apparent changes were in the offing. Although the NHL season was a downer, Belfour was a member of Canada's gold medal winning team at the Salt Lake City Olympics. During the summer of 2002, Belfour inked a multiyear contract with the Toronto Maple Leafs, replacing the departed Curtis Joseph as the team's number one netminder.

Belfour led the Dallas Stars to the Stanley Cup championship in 1999.

In 2005, the netminder surpassed Terry Sawchuck for second place in all time wins by a goaltender, however finished the season with a lackluster .500 record on a Leaf club that failed to make the playoffs for the first time in seven seasons. In the 2006 off-season, Toronto Maple Leaf General Manager John Ferguson released Ed Belfour. The veteran netminder would sign with the Florida Panthers where he would split his time with Alex Auld in goal. During that season, an injury to Auld allowed for Belfour to regain his form and post a 2.79 GAA and .902 save percentage while going 27-17-10 in the crease. After his time in Florida, Belfour signed as a free agent with Leksands IF in the Swedish second division.

The Eagle landed in Toronto for three seasons from 2002-2006.

Ed Belfour was the NHL's rookie of the year in 1991, winning the Calder Memorial Trophy. He won the William Jennings Trophy (best goals-against average) on four occasions: 1991, 1993, 1995 and 1999 (shared with Roman Turek). He also won the Vezina Trophy as the NHL's best netminder in 1991 and 1993. Ed was named to the NHL's First All-Star Team in 1991 and 1993, and to the Second Team in 1995. Along with the Stanley Cup in 1999, Belfour can now add one further accolade — membership in the Hockey Hall of Fame in 2011.