Adrian Constantine Anson (April 17, 1852 – April 14, 1922), nicknamed "Cap" (for "Captain") and "Pop", was a National Association and Major League Baseball first baseman. He played a record 27 consecutive seasons, and was regarded as one of the greatest players of his era and one of the first superstars of the game.

Anson spent most of his career with the Chicago Cubs franchise (then known as the "White Stockings" and later the "Colts"), serving as the club's manager, first baseman and, later in his tenure, minority owner. He led the team to five National League pennants in the 1880s. Anson was one of baseball's first great hitters, and the first to tally over 3,000 career hits.

His contemporary influence and prestige are regarded by historians as playing a major role in establishing the racial segregation in professional baseball that persisted until the late 1940s.. However, a 2006 biography of Anson that exhaustively examined 19th-century newspaper reporting related to him on the subject of racism reached the following conclusion: "As far as the nineteenth century, he rightfully should endure as the big leaguer who, until the late 1940s, was involved in the greatest number of reported negative incidents, on the field, relating to blacks." On several occasions, Anson refused to take the field when the opposing roster included black players. "But at the same time, his argumentative nature could be readily discounted by those around him. So, the notion that he had 'coattails' in persuading players and officials on other teams to do as he did is rather spurious."