János Székely (born 7 July 1901 in Budapest, died 16 December 1958 in East Berlin) was a Hungarian writer and screenwriter. His best-known work is the 1949 autobiographical novel Kísértés (Temptation).

He published some of his books under the pen name John Pen. Further alternative names of his were Hans Székely and John S. Toldy. At the age of 18, he fled World War I, from Hungary to Germany. In Berlin, he wrote numerous screenplays for silent movie stars like Brigitte Helm, Willy Fritsch, Marlene Dietrich and Emil Jannings. Ernst Lubitsch in 1934 invited him to work in Hollywood. In 1938 he emigrated to the United States and became a sought-screenwriter for silent and sound films. In 1940 he was awarded the Academy Award for Best Story for Arise, My Love. In the McCarthy era, he left the United States, moved to Mexico, and in 1957 to East Berlin to work with DEFA.