Moses Fleetwood "Fleet" Walker (October 7, 1856 – May 11, 1924) was an American professional baseball catcher who, historically, was credited with being the first black man to play in Major League Baseball (MLB). A native of Mount Pleasant, Ohio, and a star athlete at Oberlin College as well as the University of Michigan, Walker played for semi-professional and minor league baseball clubs before joining the Toledo Blue Stockings of the American Association (AA) for the 1884 season.

Though research by the Society for American Baseball Research (SABR) indicates William Edward White was the first African-American baseball player in the major leagues, Walker, unlike White (who passed as a white man and self-identified as such), was the first to be open about his black heritage, and to face the racial bigotry so prevalent in the late 19th century United States. His brother, Weldy, became the second black athlete to do likewise later in the same year, also for the Toledo ball club. Walker played just one season, 42 games total, for Toledo before injuries entailed his release.

Walker played in the minor leagues until 1889, and was the last African-American to participate on the major league level before Jackie Robinson broke baseball's color line in 1947. After his baseball career, he became a successful businessman and inventor. As an advocate of black nationalism, Walker also jointly edited a newspaper, The Equator, with his brother. He published a book, Our Home Colony (1908), to explore ideas about emigrating back to Africa. He died in 1924 at the age of 67.