It was built in Port Jefferson as a common meeting place for the town and at one point functioned as the high school gymnasium after a fire.

The building that was built as basically a large cube was finally cut in half to produce the theatre upstairs with raked seating and lobbies and a second stage underneath.

Theatre Three's Second Stage has produced an outstanding roster of cutting-edge dramas (including Blood Knot, The Puppetmaster of Lodz, A Man with Connections, Samm-Art Williams Home, Agnes of God, My Sister in This House, Three Tall Women, and Death and the Maiden) and delightful comedies (Shirley Valentine, Frankie and Johnny in the Clair de Lune, and The Mystery of Irma Vep).

The Second Stage has hosted such cabaret luminaries as Tovah Feldshuh, K. T. Sullivan, Marilyn Sokol, Julie Wilson, Billy Stritch, and Nancy LaMott.

The in-house Children's Theatre has presented programs on a wide array of subjects: the dangers of smoking (Puff-The-Not-So-Magic Dragon), honesty (The Boy Who Cried Werewolf), and race relations and the homeless (The Three Little Pigs, or Home Is Where You Hold Your Heart).

From the Fires: Voices of the Holocaust, the most recent addition to Theatre Three's touring productions, has been seen in schools and community centers on Long Island, as well as in Manhattan and in four other states, for a total of over 200 performances in the past three years.