List of Major League Baseball longest losing streaks

This is a list of the longest team losing streaks in Major League Baseball history. Streaks started at the end of one season are carried over into the following season. Two lists are provided—one with streaks that consist entirely of regular-season games and one with streaks of playoff games only.

The 1889 Louisville Colonels hold the record for the longest losing streak in official MLB history at 26 games, though the 1875 Brooklyn Atlantics lost 31 consecutive games in the National Association, a number that is not considered official by MLB. In the modern two-league era, the longest losing streak belongs to the 1961 Philadelphia Phillies at 23 games. In the American League, the 1988 Baltimore Orioles hold the record at 21 games. The longest ever losing streak consisting entirely of postseason games belongs to the Boston Red Sox, who following their historic loss in the 1986 World Series were swept in three consecutive postseason appearances from 1988 to 1995, losing a total of 13 games in a row.

The longest losing streak by a defending World Series Champion is 11 by both the 1998 Florida Marlins (Now Miami Marlins) (2x) and the 1986 Kansas City Royals.

This list contains only the top 20 streaks consisting entirely of regular-season games.

This list contains only streaks consisting entirely of postseason games.

This list includes streaks that involve both regular season games and games which occurred in the playoffs.

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