Merle Maddern, a prominent New York stage actress in the 1930's and 40's, died Sunday in Denver at Bethany Care Center.

She was 96 years old.

Miss Maddern, who was born on Nov. 3, 1887, was a niece of the novelist Jack London. She appeared in many productions of Eva Le Gallienne's Civic Repertory Theater, and she played on Broadway with Miss Le Gallienne in ''Hedda Gabler.'' She also appeared on Broadway with Katharine Cornell in ''Antigone'' and ''Romeo and Juliet.''

There are no survivors.