Otto Gmeling or Gmelin, also known as Grand Otto (5 July 1876 – 29 October 1925), was a German and president of FC Barcelona from 1909–1910.

He was president of the club when they won their first domestic title, the Copa del Rey in 1910.

They also won a Catalan championship undefeated and their first Pyrenees Cup.

Under Gmelings presidency, the club gained a gradual increase in the number of spectators who came to watch the games, which marked the transition from amateur to professional football.