Lexie Grey is a fictional character from the television series Grey's Anatomy. She is portrayed by actress Chyler Leigh and first appears in the show's third season. Lexie is introduced as the half-sister of Meredith Grey, the main character, and is known for her intelligence and dedication to her medical career. Throughout her time on the show, Lexie develops strong relationships with other characters, including Mark Sloan and Jackson Avery. She is often referred to as "Lexipedia" due to her extensive medical knowledge. Lexie's character experiences significant growth and challenges before her departure from the series in season 8.