In domestic football, the club has won a total of four league titles, six Coupes de France and one Trophée des Champions since its foundation.

Owned by investment fund Merlyn Partners SCSp and headed by Olivier Létang, they are the fifth-most followed French sports club on social media.

For its first season, the newborn club reached the 1945 Coupe de France final, with a squad composed of the best players of both merging teams, who are mostly natives of the Nord department.

[7] Next season, Lille won the double, beating Red Star in the 1946 Coupe de France Final and finishing at the first place of French Division 1 ahead of Saint-Étienne and Roubaix-Tourcoing.

In 1947, Lille finished in the fourth place but came back to the Coupe de France final and retained the trophy, defeating Strasbourg.

The club won the cup again in 1948 beating main rivals Lens, its third in a row, and were runners-up of the league the same year, behind Marseille that became the champions after a strong 1947–48 season finishing.

[7] On 24 June 1951, an exhausted Lille reached the Latin Cup final and lost against Gre-No-Li's AC Milan after having played 250 minutes in the span of two days.

Failing to rebuild a top team due to the increasingly poor financial situation, the club began a series of promotions and relegations.

During this period of austerity where the National Football League prohibited the club from recruiting, LOSC had to part ways with its star players, such as Antoine Sibierski or Miladin Bečanović, and chose to develop its youth academy.

[7][11] In just its first season back in the top flight 2000–01 French Division 1, Lille qualified for Europe for the first time in the club's history, booking its place in the 2001–02 Champions League.

On the back of the club's new status, Lille entered into a decisive new era under the guidance of chairman and chief executive officer Michel Seydoux and coach Claude Puel.

Amongst its most emphatic results was the 1–0 victory over Manchester United at the Stade de France in 2005, the 2–0 triumph over Milan in San Siro in 2006 and the 1–0 home win over Liverpool in 2010.

First, the inauguration of the vast and modern Domaine de Luchin training complex in 2007 brings the club to a new era, the center being one of the largest in France.

Successive strong results and a sporting progression under head coach Rudi Garcia took the club back to the top of the French league.

In November 2017, Bielsa was suspended by Lille following an unauthorized trip to Chile with the club lying second from bottom on the table again and only managing 3 wins from the first 14 games of the season.

On 14 April 2019, before a record attendance of 49,712 spectators, they defeated Paris Saint-Germain in a historic and storming 5–1 home win with goals from Nicolas Pépé, Jonathan Bamba, Gabriel and team captain José Fonte.

[23] At the end of the season, Lille secured the second place to qualify for the 2019–20 UEFA Champions League group stage; they returned to the competition after a seven-year absence.

[25] Lille announced the recruitment of Victor Osimhen and Tiago Djaló on the same day, after the signings of Timothy Weah, Reinildo Mandava and Benjamin André a few weeks earlier.

However, the Ligue 1 season ended abruptly as the LFP first suspended domestic leagues indefinitely following the outbreak of COVID-19 in France on 13 March, and then definitely cancelled French football competitions a month and a half later.

[27] In the 2020 summer transfer window, Lille chose to sign young talents Sven Botman and Jonathan David as well as veteran Burak Yılmaz.

[28] At the end of the 2020–21 season first half, Lille had only lost two games and was well installed in the top league rankings, having defeated Derby du Nord rivals Lens in a 4–0 home win on 18 October 2020.

[30] Three weeks later, Lille came back from two goals down to beat Lyon at Groupama Stadium as Burak Yılmaz scored twice including a 27-yard free kick in a breathtaking 3–2 away win.

[33] Competing also in the 2020–21 UEFA Europa League, they defeated AC Milan at San Siro, on 5 November 2020, in a big 3–0 away win with a hat-trick from Yusuf Yazıcı, but lost to Ajax in round of 32.

[34] In the 2021–22 season, Lille won its first Trophée des Champions, defeating Paris Saint-Germain with a Xeka goal at Bloomfield Stadium in Tel Aviv, Israel on 1 August 2021.

[35] The Northmen then reached UEFA Champions League round of 16 and are defeated by Chelsea, after qualifying from the group stage against Salzburg, Sevilla and Wolfsburg.

[51] The club exceptionally returns to a white home kit for the 2016–17 Ligue 1 season in order to celebrate the league and cup double 70-year anniversary.

[58] The first main sponsors of the club were Jean Caby butchery [fr] that appeared two seasons in the front of the jersey, and Lille-made Pel d'Or lemonade, produced by the very famous Pelforth brewery.

[64][65] Located inside the citadel park, not far from the former venue, the stadium's original capacity was 25,000 at the time it was opened, but this was reduced to around 17,000 by 2000 due to the evolution of safety standards.

[66] However, it still failed to meet FIFA licensing regulations and plans to build a new stadium compliant with UEFA's standards were made in 2002, when the club was privatized.

[67] In June 2003, the club's board agreed to a new proposal put forward by the city mayor to build a new 33,000-seat stadium on the site of the Stade Grimonprez-Jooris.