This is a list of the longest team losing streaks in Major League Baseball history.
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 and 2024 Chicago White Sox hold the record at 21 games.
The longest losing streak by a defending World Series Champion is 11, by the 1998 Florida Marlins and the 1986 Kansas City Royals.