He was a key member of the Algonquin Round Table, and received the Pulitzer Prize for Drama in 1930.

Connelly attended Trinity Hall boarding school in Washington, Pennsylvania, after which he began collecting money for ads in The Pittsburgh Press to help to support his mother.

[citation needed] While he was working in Pittsburgh, Connelly ventured into writing for the stage, creating skits for shows put on by an athletic association and one-act plays for a little theater group.

Over the years, Connelly appeared as an actor in 21 movies, including The Spirit of St. Louis (1957) with James Stewart.

The 1994 film Mrs. Parker and the Vicious Circle, a fictional account of the group, featured actor Matt Malloy as Connelly.