Did You Know? Major League Soccer (MLS) is a men’s professional soccer league sanctioned by the United States Soccer Federation, which represents the sport’s highest level in the United States. The league comprises 28 teams with 25 in the U.S. and 3 in Canada. It will expand to 29 teams for the 2023 season. The league is headquartered in Midtown Manhattan. Major League Soccer is the most recent of a series of men’s premier professional national soccer leagues established in the United States and Canada. The predecessor of MLS was the North American Soccer League (NASL), which existed from 1968 until 1984. The MLS was founded in 1993 as part of the United States’ successful bid to host the 1994 FIFA World Cup.