Adam Troy Dunn (born November 9, 1979), nicknamed "Big Donkey", is an American former professional baseball left fielder and first baseman. He played in Major League Baseball (MLB) for the Cincinnati Reds, Arizona Diamondbacks, Washington Nationals, Chicago White Sox, and Oakland Athletics. He is a two-time MLB All-Star.

Dunn batted left-handed and threw right-handed. He is 6 feet 6 inches (1.98 m) in height and weighs 285 pounds (129 kg). He is tied for most opening day home runs at 8 with Frank Robinson and Ken Griffey, Jr., and on August 18, 2012, he became the 50th MLB player to hit 400 career home runs. He also ranked third on the all-time strikeout list at the time of his retirement, with 2,379, and fourth for the most Golden sombreros (at least four strikeouts in a game) at 19, tied with Bo Jackson. He also holds the American League record for most strikeouts in a season with 222, which he set in 2012.