The ATP Tour 250 tournaments (previously known as the ATP World Tour 250 tournaments, ATP International Series, and ATP World Series) are the lowest tier of annual men's tennis tournaments on the main ATP Tour, after the four Grand Slam tournaments, ATP Finals, ATP Tour Masters 1000 tournaments, and ATP Tour 500 tournaments.
As of 2019, the series includes 39 tournaments, with 250 ranking points awarded to each singles champion—which accounts for the name of the series. Draws consist of 28, 32, or 48 for singles and 16 for doubles.
^ became an ATP Tour 500 event (i) refers to indoor stadiums
1990–1999 ATP World Series
2000–2008 ATP International Series
2009–2018 ATP World Tour 250
2019–present ATP Tour 250
- Players with byes receive first round points.
^ Active players in bold.*