Lille Olympique Sporting Club (commonly known as Lille) is a professional football club based in the Lille district of Nord department, Hauts-de-France region, France. It competes in Ligue 1 (the French top-flight league) and plays its home matches at the Stade Pierre-Mauroy. On September 23, 1944, two clubs—Lille Olympique and Sporting Club Fivois—merged to form Lille Olympique Sporting Club. In the 1945-46 season, Lille won both the Ligue 1 title and the Coupe de France for the first time, achieving a domestic double. In the 1947-48 season, Lille secured a third consecutive Coupe de France title and finished as runners-up in Ligue 1. From the 1950s to the 1970s, Lille became a "yo-yo team" in Ligue 1, frequently being promoted and relegated between Ligue 1 and Ligue 2. In the 2000-01 season, newly promoted Lille caused an upset by finishing third in Ligue 1, earning a spot in the UEFA Champions League qualifying rounds. In the 2004-05 season, Lille finished as Ligue 1 runners-up and topped their group to advance in the UEFA Europa League. The 2005-06 season saw Lille reach the round of 16 in the Europa League and finish third in Ligue 1, qualifying for the Champions League again. In the 2010-11 season, Lille claimed the Ligue 1 and Coupe de France double. In the 2018-19 season, they finished as Ligue 1 runners-up, returning to the Champions League. In the 2020-21 season, Lille defeated rivals Paris Saint-Germain, Monaco, and Lyon twice each in Ligue 1, securing their fourth Ligue 1 title. In the 2023-24 Ligue 1 season, Lille finished fourth, qualifying for the Champions League qualifying rounds. In the 2025 Champions League round of 16, Lille lost 2-3 to Borussia Dortmund, failing to reach the quarter-finals. In Ligue 1, Lille finished fifth, qualifying for the 2025-26 Europa League group stage.