Hayden Andrew Penn (born October 13, 1984) is an American former professional baseball player.

He went 7–4 with an ERA of 2.26 through 14 starts for the Class AAA Ottawa Lynx in 2006 and was called up to Baltimore again when the major league rosters expanded on September 1.

He made his first start of the season for Baltimore on September 3 against the Oakland Athletics; he gave up eight runs in two-thirds of an inning, for an ERA of 108.00, and took the loss.

[1][2] Penn was traded to the Florida Marlins on April 1, 2009 in exchange for infielder Robert Andino.

Penn was waived by the Marlins during the 2010 Spring Training and claimed by the Pittsburgh Pirates,[4] making their opening day roster.