Dennis Joseph "Dan" Brouthers (/ˈbruːθərz/ (May 8, 1858 – August 2, 1932) was an American first baseman in Major League Baseball whose career spanned the period from 1879 to 1896, with a brief return in 1904. Nicknamed "Big Dan" for his size, he was 6 feet 2 inches (1.88 m) and weighed 207 pounds (94 kg), which was large for 19th-century standards. Recognized as the first great slugger in baseball history, and amongst the greatest sluggers of his era, he held the record for career home runs from 1887 to 1889, with his final total of 106 tying for the fourth most of the 19th century. His career slugging percentage of .519 remained the major league record for a player with at least 4,000 at bats until Ty Cobb edged ahead of him in 1922. At the time of his initial retirement, he also ranked second in career triples (205), and third in runs batted in (1,296) and hits.
A dominating hitter during the prime of his career, he led (or was in the top of) the league in most offensive categories, including batting average, runs scored, runs batted in (RBI), on-base percentage and hits. He led the league in batting average five times, the most by a 19th-century player, and his career .342 batting average still ranks ninth all-time. He was also an active players' union member, and was elected vice president of the Brotherhood of Professional Base Ball Players. His career achievements led to his election into the Baseball Hall of Fame by the Veterans Committee in 1945.