Ben Sheets with 1206.
Camilo Pascuel
Randy Johnson has the most strikeouts by a left handed pitcher. He also has the second most strikeouts all-time and over 300 wins.
Nolan Ryan holds the career record with 5,714 strikeouts.
Nolan Ryan with 1866.
Nolan Ryan has the most career strikeouts with 5,714.
Tom Cheney of the Washington Senators holds the MLB record for most strikeouts in a single game when he struckout 21 Baltimore Orioles batters in a 16 inning game in 1962. Kerry Wood, Randy Johnson, and Roger Clemens (twice) hold the MLB record for most strikeouts in a 9 inning game with 20. == ==
Johan Santana with 265 strikeouts in 2004.
In 2012, Justin Verlander of the Detroit Tigers, had the most strikeouts with 239.
Sandy Koufax with 382 strikeouts in 1965.
15.
Nolan Ryan
At the time of this question, Mark Buehrle had the most strikeouts, but currently Freddy Garcia does.