Jeremy Affeldt is a retired American professional baseball player who played as a pitcher in Major League Baseball (MLB) for 14 seasons. He was born on June 6, 1979, in Phoenix, Arizona, and attended Northwest Christian High School in Phoenix. Affeldt was drafted by the Kansas City Royals in the third round of the 1997 MLB draft and made his MLB debut with the Royals in 2002.

Affeldt played for the Royals from 2002 to 2006, during which he was primarily used as a relief pitcher. In 2007, he signed with the Colorado Rockies, where he played for one season before being traded to the Cincinnati Reds. Affeldt played for the Reds from 2008 to 2009, during which he was a key member of the team's bullpen.

In 2009, Affeldt signed with the San Francisco Giants, where he played for the remainder of his career. He was an integral part of the Giants' bullpen during their World Series championship runs in 2010, 2012, and 2014. Affeldt was known for his ability to pitch in high-pressure situations and was often called upon to pitch in the late innings of close games.

Throughout his career, Affeldt was known for his versatility as a pitcher. He was able to pitch effectively as both a starter and a reliever, and was often used as a left-handed specialist due to his ability to get left-handed batters out. Affeldt was also known for his durability, as he was able to pitch in a high number of games each season without suffering any major injuries.

Off the field, Affeldt was known for his philanthropic work. He and his wife, Larisa, founded the Jeremy and Larisa Affeldt Foundation, which supports various charitable causes, including anti-human trafficking efforts and programs that help children with disabilities.

Affeldt retired from baseball in 2015, finishing his career with a record of 43-46 and an ERA of 3.97. He recorded 28 saves and struck out 636 batters in 770 innings pitched. Affeldt was widely regarded as one of the most reliable and effective relief pitchers of his era, and his contributions to the Giants' championship teams will be remembered for years to come.