Hayden Andrew Penn (born October 13, 1984 in Santee, California) is a pitcher for the Baltimore Orioles. He made his major-league debut in , when he made eight starts with the Orioles, compiling a 3-2 record with a 6.34 ERA.
In May , he suffered appendicitis after being called up by the Orioles and missed several months while recovering from it. 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.