Sammy Sosa
Reggie Jackson holds the record for the most career strikeouts by a batter with 2,597. Jim Thome (2,548), Adam Dunn (2,379), Sammy Sosa (2,306), Alex Rodriguez (2,287) and Andrés Galarraga (2,003) are the only other hitters to strikeout over 2,000 times.