Thunder Bay is a city on Lake Superior in the province of Ontario, Canada.
Thunder Bay also refers to several other things in North America's Great Lakes region.
In Canada
Thunder Bay is the name of several places in the province of Ontario:
Electoral districts in Ontario
Current
Defunct
In the United States
Thunder Bay is the name of several places in the US state of Michigan
- Thunder Bay Border Cats, a baseball team in Thunder Bay, Ontario, which is part of the collegiate summer Northwoods League
- Thunder Bay Chill, an association football team founded in 2000 in Thunder Bay, Ontario, which is part of the Premier Development League
- Thunder Bay North Stars, a Junior "A" ice hockey team founded in 2000 in Thunder Bay, Ontario, which is part of the Superior International Junior League
- Thunder Bay Northern Hawks, a Junior "B" ice hockey team founded in 1999 in Thunder Bay, Ontario, which is part of the Thunder Bay Junior B Hockey League
- Thunder Bay Fighting Walleye, a Junior "B" ice hockey team founded in 2009 in Thunder Bay, Ontario, which is part of the Thunder Bay Junior B Hockey League
Defunct
- Thunder Bay Bearcats, a Junior "A" ice hockey team in Thunder Bay, Ontario, part of the Superior International Junior League (2006–2009)
- Thunder Bay Beavers, a Junior "A" ice hockey team in Thunder Bay, Ontario, part of the Junior A League 1971–1978; previously known as the Vulcans and the Centennials
- Thunder Bay Bombers, a senior ice hockey team in Thunder Bay, Ontario; it had been previously known as the Twins
- Thunder Bay Bulldogs, a Junior "A" ice hockey team in Thunder Bay, Ontario, part of the Superior International Junior League (2001–2008)
- Thunder Bay Flyers, a Junior "A" ice hockey team in Thunder Bay, Ontario, part of the Junior A League (1980–2000); previously known as the Kings
- Thunder Bay Hornets, a Junior "A" ice hockey team in Thunder Bay, Ontario, part of the Junior A League (1982–1986)
- Thunder Bay Thunder Cats, an ice hockey team in Thunder Bay, Ontario, 1991–1999 before moving to Rockford; previously known as the Thunder Hawks and Senators
- Thunder Bay Twins, an ice hockey team in Thunder Bay, Ontario, 1970–1991, member of several leagues during its existence
- Thunder Bay Whiskey Jacks, a baseball team in Thunder Bay, Ontario, 1993–1998, one of the founding members of the independent Northern League
- Thunder Bay Wolverines, an ice hockey team in Thunder Bay, Ontario, 2003–2010