Michelle Lynn Monaghan (born March 23, 1976) is an American actress. She is best known for her starring roles in Kiss Kiss Bang Bang (2005), Gone Baby Gone (2007), Made of Honor (2008), Eagle Eye (2008), Source Code (2011), Pixels (2015), and Patriots Day (2016). She has also received recognition for her starring role as Julia Meade in the action spy film series Mission: Impossible, appearing in Mission: Impossible III (2006), Mission: Impossible – Ghost Protocol (2011), and Mission: Impossible – Fallout (2018).

On television, Monaghan starred as Maggie Hart in the first season of the anthology crime drama series True Detective (2014), for which she received a nomination for the Golden Globe Award for Best Supporting Actress. She also starred as Sarah Lane in the drama series The Path (2016–18).