Halley Wegryn Gross was born in Fort Myers, Florida on December 27, 1985, the morning after Halley's Comet appeared over the west coast of Florida. She moved from Sanibel Island to New Jersey when she was 3 1/2. At the age of 9 , inspired by the movie "The Addams Family," she began fencing and was determined to become an actress. She trained in foil with Olympic Gold Medalist Vladimir Lilov and competed for her school and fencing club.

She also began studying singing with Jackie Presti. Her first theatre and dance classes were at Worth Tyrrell studios in Morristown, New Jersey. From 1997 to 2002 she studied at Stagedoor Manor Performing Arts Camp where she performed in the "Our Time Cabaret" as well as numerous productions including performing Jeanine Tesori's musical "Violet" as the older Violet. In her junior year, she successfully competed against over 900 students (one delegate from each high school) for one of fourteen scholarships in the New Jersey Governor's School for the Arts, Theatre Division. A consistent honor roll student, she graduated from the Pingry School which she attended for 13 years. Immediately thereafter she studied at the Royal Academy of Dramatic Arts, in London. She has interned in casting at Jay Binder Casting. Fall 2004 Halley began her undergraduate studies at New York University where she is currently in the Gallatin School for Individualized Study concentrating in entertainment business.

When she is not at college or working, she continues to reside with her parents in New Jersey. She is the proud mother of two long-haired Chihuahuas, Cleopatra and Sheba, and a Maine Coon cat, Iago.