The American Soccer League has been a name used by three different professional soccer leagues in the United States.

ASL I

The original American Soccer League, operating between 1921 and 1933, was the first significant viable professional soccer league in the United States. The league operated primarily in the northeastern United States, particularly in the New York-New Jersey-Philadelphia triangle.

Additionally, the ASL was one of the first American soccer leagues prestigious enough to attract talented players from overseas. The league, in fact, was quite well attended, and was quite competitive with the nascent National Football League in terms of popularity. The combination of excellent pay and a high level of play drew talented oversees players, especially from Scotland and England. This led to a significant amount of resentment in Europe and threats of sanctions from FIFA. Then the ASL ran afoul of the US Football Association (USFA) when team owners complained that USFA's requirement that ASL teams play in the U.S. Open Cup created an unnecessary burden on the teams. At the time the Open Cup ran during the ASL season forcing the ASL teams to travel long distances by train or bus to play Open Cup games, then return to the Northeast to play league games. When the ASL decided to boycott the Open Cup, FIFA declared the ASL an "outlaw league". This sparked the "Soccer War". The ASL team owners decided to defy FIFA, relying on the league's reputation to continue to draw players. At first it seemed as if the ASL might win; however, during the 1928-1929 ASL season, FIFA and USFA gained an opportunity to undermine the ASL when three three teams, most prominently Bethlehem Steel F.C., defied the ASL and entered the Open Cup. When the ASL suspended these teams USFA offered to help bankroll the creation of a new league to rival the ASL. The three ex-ASL teams joined with several other east coast teams to create new Eastern Soccer League. The creation of a competing league, combined with the onset of the Great Depression in 1929, caused severe financial strains on the ASL. The league finally broke and came into compliance with USFA and FIFA. In the fall of the 1929/30 season, the ESL and ASL merged to form the Atlantic Coast League which started play in the spring of 1930 now playing a spring-fall schedule. In the fall of 1930 (the second half of the 1930 season), the league was renamed the American Soccer League again. However, the Soccer Wars had permanently crippled the ASL and after the end of the 1933 spring season, the league collapsed. Ironically, while USFA and FIFA "won" the wars, the spectacle of a U.S. athletic association conspiring with a European organization to undermine a U.S. athletic league alienated many non-committed U.S. sports fans. These fans turned their backs on soccer, relegating the sport to the position of a minor league, ethnic based sport for decades to come.

ASL II

In the fall of 1933, a second American Soccer League was established. This second league survived until 1983. Like the original ASL, this league primarily operated in the northeast for much of its existence. In order to compete with the North American Soccer League, the ASL went national in 1976, expanding to the west coast by adding teams in Los Angeles, Oakland, Sacramento, Salt Lake City, and Tacoma. In addition, Bob Cousy was hired as commissioner and the league changed the standings scoring system to more closely resemble the NASL. ASL teams were awarded 5 points for a win, 2 points for a tie, and 1 point for each goal up to a maximum of 3 per game (The NASL awarded 6 points for a win and 3 for a tie, with 1 for each goal up to 3 per game). The ASL also had a limit on the number of foreign players each team could have in an effort to gain popularity among American fans.

While this expansion gave the ASL national exposure, the league and teams were no match financially for the NASL. On rare occasions, an ASL team would outbid a NASL team for a recongnizable player, but more often than not, the better players in the ASL were offered more money to jump to the NASL. The high point in the history of the league may have been the 1976 championship game between the L.A. Skyhawks and N.Y. Apollo; L.A. won 2-1 in front of over 9,000 fans. But by 1979, attendance was down, every team was losing money, and the league finally folded in 1983. After the ASL II ceased operations, several of its teams formed the original United Soccer League, which played seasons in 1984 and 1985.

ASL III

The next league to call itself the American Soccer League played two seasons in 1988 and 1989. This league comprised ten teams on the Atlantic coast. During its second season, the league champion Fort Lauderdale Strikers played the San Diego Nomads, champions of the Western Soccer Alliance in a "national championship" game. By 1990, the ASL and WSA had merged to form the American Professional Soccer League.