Theo Epstein is a baseball executive who is best known for his work with the Boston Red Sox and Chicago Cubs. He was the general manager of the Red Sox from 2002 to 2011, during which time they won two World Series championships. He then became the president of baseball operations for the Cubs in 2011, and in 2016, he led them to their first World Series championship in 108 years. Epstein is considered one of the most successful executives in baseball history.