In Major League Baseball (MLB), the 300 strikeout club is a group of pitchers who have struck out 300 or more batters in a single season.
In the modern era (post-1900), 19 different pitchers have reached the 300 strikeout mark 38 times as of the 2024 MLB season.
Since 1900, Nolan Ryan and Randy Johnson have recorded the most 300-strikeout seasons, with six each.
Koufax and Curt Schilling each recorded three 300-strikeout seasons, followed by two each by Waddell, Sam McDowell, Walter Johnson, J. R. Richard, and Pedro Martínez.
[1] In the pre-modern era, with a mound closer to home plate and constant rule changes, strikeouts were more common.