The Continental League is announced as baseball's "3rd major league" in the United States.

The Continental League of Professional Baseball Clubs (known as the Continental League or CL) was a proposed third major league for baseball in the United States and Canada. Though a league by that name was proposed in 1920, its best-known incarnation was announced in 1959 and scheduled to begin play in the 1961 season. Unlike predecessor competitors such as the Players' League and the Federal League, it sought membership within organized baseball's existing organization and acceptance within Major League Baseball (as any attempt at outsider leagues could be quashed as per a 1922 Supreme Court case declaring MLB exempt from federal antitrust laws). The league disbanded in August 1960 without playing a single game as a concession by William A. Shea as part of his negotiations with Major League Baseball to expand to incorporate at least eight new teams.