1962 Major League Baseball expansion

The 1962 Major League Baseball expansion was the formation of two new Major League Baseball (MLB) teams for the 1962 season. The Houston Colt .45s (later renamed the Astros) and the New York Mets were added to the National League, becoming the 19th and 20th teams in MLB's two leagues. The Colt .45s was the first major league team in Houston while the Mets filled the void left when the New York Giants and Brooklyn Dodgers of the National League moved to California after the 1957 season.

The previous year the American League added the Los Angeles Angels and Washington Senators.

For a 50-year period from 1903 to 1952, MLB's 16-team structure (split into the American and National Leagues) remained intact. No new franchises began during this period, and five markets—Boston, Chicago, New York City, Philadelphia, and St. Louis—had two or more teams. According to authors Andy McCue and Eric Thompson, "The less financially successful clubs in two-team cities were finding it increasingly difficult to compete" by the early 1950s. In addition, population changes in the United States were leading to many citizens moving away from the Northeast, where many MLB teams were based, to southern and western locations.

From 1953 to 1955, three franchises were relocated, all of which had been in markets with two or more teams. Prior to the 1958 season, the two New York City teams in the National League, the Brooklyn Dodgers and New York Giants, moved westward; the Dodgers relocated to Los Angeles, while San Francisco became the new home of the Giants. New York City sought a replacement National League franchise, and by December 1958 MLB had created an Expansion Committee. Despite the formation of the group, MLB displayed little intention of adding a New York team. The city had beaten MLB to planning for future expansion, with the formation of the Mayor's Committee shortly after the Dodgers and Giants announced their moves; the committee was headed by lawyer William Shea.

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