Leighton Meester is an American actress and singer. She is a former cast member of Law and Order, as she portrayed the role of Alyssa Turner in the series as a guest star.Meester's character had a one-episode arc for the storyline of the episode titled 'Disciple'. The episode focused on a teenage girl found dead in an emergency room, and the investigation surrounding it. Meester played the murder victim's best friend in the series.Apart from an acting role, Leighton Meester also has singing credits for the series. She provided guest vocals to the song Good Girls Go Bad by Cobra Starship. The song was featured in the cold open of the Law & Order: Special Victims Unit season 16 episode titled 'Granting Immunity'.Who is Leighton Meester? Filmography explored View this post on Instagram Instagram PostLeighton Meester is an American actress known most prominently for her starring role as Blair Waldorf on the CW television series Gossip Girl, She played the character from 2007 to 2012.The actress has also appeared in multiple films over the years since her debut in 1999. She has also ventured into theatre as well as film and television, making her Broadway debut in Of Mice and Men (2014). Some of her major filmography includes:2003 - Hangman's Curse as Elisha Springfield2003 - Tarzan as Nicki Porter2005 - 24 as Debbie Pendleton2005 - Veronica Mars as Carrie Bishop2005–2006 - Surface as Savannah Barnett2006 - Flourish as Lucy Covner2007 - Drive-Thru as Mackenzie Carpenter2007–2012 - Gossip Girl as Blair Waldorf2008 - Killer Movie as Jaynie Hansen2010 - Date Night as Katy2011 - The Roommate as Rebecca Evans2011 - The Oranges as Nina Ostroff2012 - That's My Boy as Jamie Martin2014 - Life Partners as Sasha Weiss2014 - Like Sunday, Like Rain as Eleanor Logan2017- Making History as Deborah Revere2018–2020 - Single Parents as Angie D'Amato2019 - Semper Fi as Clara2022 - The Weekend Away as Beth2022–2023 - How I Met Your Father as MeredithAlso read: Which role did Will Sasso play on Law and Order: SVU? Everything you need to knowWhat is Law and Order about? Plot of the series exploredA still from the trailer for Law and Order season 1 (Image via Rotten Tomatoes TV / YouTube)Law and Order is an American police procedural and legal drama series. It aired its entire run on the NBC channel, premiering in September 1990. The show ran for 20 seasons till May 2010. Then, in 2021, it was revealed that the series would be revived for another season, which premiered in February, 2022.Law and Order is set and filmed in New York City, and usually follows a two-part approach for its episodes. Each episode has an individual storyline and case. The first half-hour of the installment is the investigation of a crime and its suspects. Then, the second half is the prosecution at the district attorney's office.Also read: Why Did Michael Moriarty Leave Law and Order? Details ExploredApart from Law and Order, Leighton Meeser is also likely to play an upcoming role in Netflix's Nobody Wants This, alongside Kristen Bell and Adam Brody.