Sandy Martin began her acting career at the age of 15 touring the country with Martha Raye in Good-bye Charley. After several East Coast touring productions she settled in New York City. Martin began working in many of New York City's esteemed theatres: Lincoln Center, La Mama, Ensemble Studio Theatre, Playwrights Horizon, The American Place Theatre acting in over 70 stage productions.
Martin was a founding company member for two renowned New York City's theatre companies: the Wpa Theatre and the Perry Street Theatre. During this period she played opposite Armand Assante, Christopher Lloyd, John Savage and Ellen Barkin. Martin then joined the improvisational troupe, Second City. First, in New York City at the Eastside Playhouse and the Plaza Hotel before moving on as a company member in Chicago. There she worked with John Belushi, Bill & Brian Murray, and Harold Ramis.
In 1976 Martin was asked to guest direct senior plays at the American Academy Of Dramatic Arts in both New York and Los Angeles. During this period she co-founded Hothouse Stage Co. with Susan Streitfeld. Together they produced (with Streitfeld directing and Martin acting) the award winning productions of: Hothouse (Matrix Theatre), East/West Game by John Cassavetes, (Co-staring with Nick Cassavetes at the Callboard Theatre) and Welcome to Andromeda (Matrix Theatre) ending their tenure with Best Revival of the Year - L.A. Weekly 1991, The Killing of Sister George. Sandy went on to direct - Line by Israel Horovitz (Best Direction Award - Dramalogue / (Matrix Theatre), Saturday Night by Jerome Kass (Starring Robert Pastorelli / Cast Theatre), Una Vida (Cheech Merin / Actor's Studio), Talking With... (Starring Cch Pounder). Martin also directed a reading of The Team by Terrence Feely, starring Kevin Spacey, Lenny Von Dohlan and Sheryl Lee.