Julianne Nicholson (born July 1, 1971) is an American actress. She played Det. Megan Wheeler on Law & Order: Criminal Intent, and also appeared in the HBO series Boardwalk Empire and Showtime's Masters of Sex, as well as Ivy in the film adaptation of August: Osage County. In 2016, she starred in the short-lived USA series Eyewitness.
Nicholson was born and raised in Medford, Massachusetts (outside Boston), the daughter of Kate (née Gilday) and James O. Nicholson, Jr. She is the eldest of four siblings.
After graduating from Arlington Catholic High School, she modeled in New York for six months, quit for a year, then resumed her modeling career in Paris for another six months. After returning to New York, she attended Hunter College as a general studies major for two years. While in New York, Nicholson supported herself by waitressing and eventually left school to study acting and begin her professional career.