Robert John Rinker (April 21, 1921 – December 19, 2002) was an American professional baseball player who appeared in three Major League games as a pinch hitter and catcher for the 1950 Philadelphia Athletics. The native of Audenried, Pennsylvania, batted and threw right-handed, stood 6 feet (1.8 m) tall and weighed 190 pounds (86 kg). Rinker's professional career lasted three seasons, beginning in 1948 and ending immediately after his September 1950 audition with the Athletics in the waning days of Connie Mack's 50-year tenure as the team's manager.