Here are a list of NHL teams that no longer exist. The teams have either moved, withdrawn, folded, merged with (an)other franchise(s) or changed their names.
- Montreal Wanderers (1917-1918, withdrew after arena burned down)
- Toronto Arenas (1917-1919, renamed Toronto St. Pats)
- Toronto St. Pats (1919-1926, renamed Toronto Maple Leafs)
- Ottawa Senators (1917-1934, original incarnation folded)
- Quebec Bulldogs (1919-1920, folded)
- Hamilton Tigers (1920-1925, disbanded after players went on strike)
- Montreal Maroons (1924-1938, folded)
- New York Americans (1925-1942, renamed the Brooklyn Americans)
- Pittsburgh Pirates (1925-1930, folded)
- Detroit Cougars (1926-1930, renamed Detroit Falcons)
- Detroit Falcons (1930-1932, renamed Detroit Red Wings)
- Philadelphia Quakers (1930-1931, folded)
- St. Louis Eagles (1934-1935, folded)
- Brooklyn Americans (1942-1943, folded)
- Oakland Seals (1967-1970, renamed California Golden Seals)
- Minnesota North Stars (1967-1993, merged with San Jose Sharks and moved and became Dallas Stars)
- Atlanta Flames (1972-1980, moved and became Calgary Flames)
- Kansas City Scouts (1974-1976, moved and became Colorado Rockies)
- California Golden Seals (1970-1976, folded and became Cleveland Barons)
- Cleveland Barons (1976-1978, folded and merged with Minnesota North Stars)
- Colorado Rockies (1976-1982, moved and became New Jersey Devils)
- Hartford Whalers (1979-1997, moved and became Carolina Hurricanes)
- Quebec Nordiques (1979-1995, moved and became Colorado Avalanche)
- Winnipeg Jets (1979-1996, moved and became Phoenix Coyotes)
That means, including active team names, there have been 53 different team names in NHL history (or 54 if you consider the two distinct Ottawa Senators franchises as different).
Note: this does not include every team that has won the Stanley Cup. The NHL did not come into existance until the 1917-1918 season, but there were Stanley Cup winners from 1892-1917. That list is for another node.