Lech has won the Polish league a total of eight times, most recently in 2022, and is the most popular football club in the Greater Poland region.

[5] In August 1920, a group of young teenagers from the Catholic Youth Association decided to split off and form their own football team.

At first, the club was not admitted to the top flight, but the Kolejorz ("the railwayman", the popular nickname of the club) filed an appeal and the PZPN decided, in a special meeting, to extend the First Division to 14 teams, including the KKS (at that time called Kolejowy Klub Sportowy Poznań) and Widzew Łódź.

Kopa gathered players at a training camp in Błażejewko, saved the team from relegation and twelve months later qualified for the first time to play in Europe after finishing third in the league, just two points behind the champion, Wisła Kraków.

Two years later, the club managed to win the first title in its history, the Polish Cup, by defeating Pogoń Szczecin 1–0 in Wrocław.

The 15 goals scored by the top scorer of the tournament, Mirosław Okoński and the participation of other players like Krzysztof Pawlak and Józef Adamiec were very important to win their first league championship.

That season was historic for the blue team, as they got their first double by becoming champions of the Polish Cup, after winning in the final at Wisła Kraków (3–0).

In the first leg in Poland, Mariusz Niewiadomski and Mirosław Okoński scored the first two Lech goals in the tournament and the team won 2–0.

Andrzej Juskowiak was the top scorer of the tournament with 18 goals and his team finished with 42 points, two more than the runner-up, Zagłębie Lubin.

Smuda formed a strong team with the arrival at the club of players like Robert Lewandowski, Hernan Rengifo, Semir Štilić, Marcin Zając and Rafał Murawski.

On 19 May 2009, Lech won the Cup for the fifth time by beating Ruch Chorzów with a solo goal by Sławomir Peszko at Stadion Śląski.

One of their most successful European appearance was in the 2010–11 UEFA Europa League, in which they eliminated Dnipro Dnipropetrovsk to enter the group stage of the tournament for the first time.

In the 2021–22 season, during which Lech celebrated its 100th anniversary, the team led by Maciej Skorża finished runners-up in the Polish Cup, losing 3–1 against Raków Częstochowa,[10] and won the club's eighth championship, their first in seven years.

[11] Skorża left the team shortly after, citing personal reasons, and was replaced by Dutchman John van den Brom for the 2022–23 season.

Lech crashed out of the UEFA Champions League first qualifying round after losing to Azerbaijani side Qarabağ 1–5 on aggregate.

[12] The team went on to have a successful UEFA Europa Conference League campaign, reaching second place in the group stage which included Villarreal, Austria Wien and Hapoel Be'er Sheva,[13] then eliminating Nordic teams Bodø/Glimt and Djurgårdens IF to reach the quarter-finals,[14] where their successful run ended after a 4–6 defeat on aggregate to Fiorentina.

Lech failed to progress past the third qualifying round of the Europa Conference League, losing to Slovak side Spartak Trnava 3–4 on aggregate, despite winning the first game at home 2–1.

[17] In December 2023, trailing in the league by eight points by the winter break, van den Brom was dismissed and replaced with Mariusz Rumak,[18] returning to the role after nine-and-a-half years.

Lech's form did not improve under Rumak; they were unable to take the lead in the table, lost to lower-placed teams Puszcza Niepołomice and Ruch Chorzów,[19][20] and were eliminated from the 2023–24 Polish Cup after conceding in the 119th minute of a quarter-final match against Pogoń Szczecin.

During the 2008–09 UEFA Cup season, Lech made it to the group stage of the competition after knocking out higher seeded teams of Grasshopper (notching its greatest margin of victory with a 6–0 win at home) and Austria Wien (scoring the decisive goal in the last minute of extra-time).

In the group stage, Lech finished third-placed ahead of Nancy and Feyenoord to secure a place in the Third Round, where it was knocked out by the Italian side Udinese.

Their home ground Stadion Poznań has been totally rebuilt and completed in September 2010 for UEFA Euro 2012, during which it is expected to host 3 games in Group C.

Source: Lech Poznań Initially the club's first stadium was located in the Dębiec district between two train tracks.

Lech Poznań is considered to have one of the strongest fan support in Poland due to the club's high average attendance in the Ekstraklasa and the atmosphere during the games.

For over a decade Lech supporters have a fellowship with fans from Arka Gdynia and KS Cracovia sometimes called the Wielka Triada or The Great Triad.

Relations with local rival Warta Poznań are neutral as the clubs have almost always played in different leagues and many fans attend matches of both teams.

The fans' goal celebration involving the turning of their backs to the pitch, joining arms and jumping up and down in unison—originated in 1961[citation needed].

It is known in the English speaking world as "The Poznan" after Manchester City began using the celebration following their clash with Lech Poznań in the group stages of the 2010–11 UEFA Europa League.

Many Polish rappers who hail from Poznań have been strongly linked to the Lech supporter scene and the club prominently features in their music.