Harley Jane Kozak (born January 28, 1957) is an American actress and author. She made her film debut in the horror film The House on Sorority Row (1982), and had a recurring role as Mary Duvall on the soap opera Santa Barbara between 1985 and 1989. She later had supporting parts in Clean and Sober (1988) and When Harry Met Sally... (1989), before starring in the major studio films Parenthood (1989) and Arachnophobia (1990).
Kozak continued to act in film throughout the remainder of the 1990s and into the 2000s, but turned her focus to writing. She has published five mystery novels since 2004. Her debut novel, Dating Dead Men, earned her an Agatha, Anthony, and Macavity Award.
Kozak was born Susan Jane Kozak in Wilkes-Barre, Pennsylvania, the daughter of Dorothy (née Taraldsen), a university music teacher, and Joseph Aloysius Kozak, an attorney. She has seven older siblings. Their father died when Harley was a year old. She was raised in Lincoln, Nebraska. Kozak relocated to New York City after high school, and worked as a waitress for ten years. She attended New York University's Graduate Acting Program at the Tisch School of the Arts, graduating in 1980.