Jason Thomas Berken (born November 27, 1983) is an American former professional baseball pitcher. He has played in Major League Baseball (MLB) for the Baltimore Orioles and Chicago Cubs.
Berken graduated from West De Pere High School. He played college baseball for the Clemson Tigers. While at Clemson, he played for the New England Collegiate Baseball League's Keene Swamp Bats. In 186⁄3 innings with Clemson, Berken pitched to an 18–6 record, 3.04 ERA, and 156 strikeouts.
Berken was drafted by the Baltimore Orioles in the sixth round (175th overall) of the 2006 MLB draft. On May 26, 2009, after pitching just 25⁄3 innings for Triple-A Norfolk, he was called up to the Orioles' roster to replace injured outfielder Lou Montanez. He earned his first major league win that day, giving up two runs in five innings in a 7–2 victory over the Toronto Blue Jays. However, he finished the year with a 6–12 record, along with a 6.54 ERA in 119⁄3 innings pitched. This led to Berken being named the "AL Les Sweetland Award winner" by SI writer Joe Posnanski for finishing the year as the worst starting pitcher in the American League.