Betty Jo Hawkens, 55, an adjunct professor with American University's department of performing arts and an actress and monologist, died Monday of respiratory failure at the Lynn House Nursing Center in Alexandria.

Mrs. Hawkens was born in Wichita Falls, Tex. She attended Rice University in Houston, and Hardin Junior College, now Midwestern University, in Wichita Falls before graduating from the Pasadena Playhouse College of Theatre Arts in California.

She began her acting career performing monologues on a Houston radio station in 1946 and soon after went to New York City, where she first played in a New York Theater Guild production of "Angel Street."

In 1950, while playing the role of Ado Annie in London's Drury Lane Royal Theater production of "Oklahoma," she met her husband, retired Air Force Col. Edward A. Hawkens, who was then stationed in London.

She subsequently played leading roles in plays by Tennessee Williams and Eugene O'Neill and frequently performed monologues, including some that she wrote herself.

In recent years, Mrs. Hawkens worked as an adjunct professor at American University, where she earned a master's degree in drama. In 1976, she directed and starred in the university's production of "Hugger Mugger."

She was active in the First Church of Christ Scientist.

Besides her husband, of the home in McLean, and a daughter, Susan V. Mosley of Washington, survivors include two sons, Navy Lt. Edward R., on submarine duty, and David A., of Fredericksburg, Va.

The family suggests that expressions of sympathy be in the form of contributions to the Lynn House Nursing Center in Alexandria. CAPTION: Picture, BETTY JO HAWKENS