Marjorie Monaghan (born March 19, 1964) is a California-born American actress. Raised in Cincinnati, Ohio, she is best known for her portrayal in 1997 and 1998 of Theresa Halloran in the television series Babylon 5. Monaghan was born March 19, 1964 in Orange County, California. She is of Irish-Celt ancestry and started acting in high school.