Julianne Nicholson (born July 1, 1971) is an American actress. She is best known for her roles in the films August: Osage County (2013) and Blonde (2022), as well as the television series Law & Order: Criminal Intent (2006–2009), Masters of Sex (2013–2014), Eyewitness (2016), and Mare of Easttown (2021), the lattermost of which earned her a Primetime Emmy Award.
Nicholson's other notable credits include Tully (2000), Ally McBeal (2001–2002), Kinsey (2004), Conviction (2006), Boardwalk Empire (2011–2013), Black Mass (2015), I, Tonya (2017), Togo (2019), and The Outsider (2020).

The Amateur
Director O'Brien
2025

Dope Girls
Kate Galloway · (6 episodes)
2025

Paradise
Samantha 'Sinatra' Redmond · (8 episodes)
2025

Janet Planet
Janet
2024

Dream Scenario
Janet Matthews
2023

Blonde
Gladys
2022

Weird: The Al Yankovic Story
Mary Yankovic
2022

With/In Volume 2
2022

With/In Volume 2
(segment "Touching")
2021

Hacks
Dance Mom · (3 episodes)
2021

Mare of Easttown
Lori Ross · (7 episodes)
2021

The Outsider
Glory Maitland · (10 episodes)
2020

Togo
Constance Seppala
2019

Initials S.G.
Jane
2019

Monos
Doctora
2019

Weightless
Janeece
2018

Who We Are Now
Beth
2018

I, Tonya
Diane Rawlinson
2017

Novitiate
Nora Harris
2017

Law & Order True Crime
Jill Lansing · (2 episodes)
2017

From Nowhere
Jackie
2017

Eyewitness
Helen Torrance · (10 episodes)
2016

Sophie and the Rising Sun
Sophie Willis
2016

Black Mass
Marianne Connolly
2015

10,000 Saints
Harriet
2015

The Red Road
Jean Jensen · (12 episodes)
2014

August: Osage County
Ivy Weston
2013

Masters of Sex
Dr. Lillian DePaul · (12 episodes)
2013

Keep the Lights On
Claire
2012

Shadows & Lies
Ann
2010

Brief Interviews with Hideous Men
Sara
2009

The Good Wife
Callie Simko · (2 episodes)
2009

Staten Island
Mary Halverson
2009

Flannel Pajamas
Nicole
2006

Two Weeks
Emily Bergman
2006

The Megan Mullally Show
Self - Guest · (1 episode)
2006

Puccini for Beginners
Samantha
2006

Conviction
Sara Finn · (13 episodes)
2006

The Water Is Wide
Barbara
2006

Her Name Is Carla
Carla
2005

Kinsey
Alice Martin
2004

Little Black Book
Joyce
2004

Seeing Other People
Alice
2004

Tully
Ella Smalley
2002

Presidio Med
Dr. Jules Keating · (16 episodes)
2002

I'm with Lucy
Jo
2002

Speakeasy
Rebecca
2002

Dead Dog
Charity
2001

Law & Order: Criminal Intent
Megan Wheeler · (24 episodes)
2001

Godass
Nancy
2000

The Others
Marian Kitt · (13 episodes)
2000

Passion of Mind
Kim
2000

The Love Letter
Jennifer
1999
Harvest
Lou Yates
1999

Storm of the Century
Katrina Withers · (3 episodes)
1999

Curtain Call
Sandra Hewson
1998

One True Thing
College Student
1998

Long Time Since
Vivian James / Phoebe
1998

Dellaventura
Carol Dakin · (1 episode)
1997

Ally McBeal
Jenny Shaw · (10 episodes)
1997

ER
Jordan · (2 episodes)
1994

Law & Order
Jessie Lucas · (1 episode)
1990

Hallmark Hall of Fame
Barbara · (1 episode)
1951