He is a part owner of Polish football club Wisła Kraków,[3] where he began his professional career and established himself at a young age.

In 2007, he joined Borussia Dortmund, where he spent the majority of his career, making over 250 appearances and winning two Bundesliga titles, two DFL-Supercups, and one DFB-Pokal.

His uncle, former Poland captain Jerzy Brzęczek, then helped him get a trial at Wisła Kraków, where he impressed then-manager Werner Lička.

[6] Błaszczykowski quickly broke into Wisła's first team, with his first league appearance coming on 20 March 2005 against Polonia Warsaw.

[7] In February 2007, Błaszczykowski signed a four-year contract with Borussia Dortmund for an undisclosed fee, joining the Bundesliga side in July of that year.

FC Nürnberg, sending Dortmund on their way to a 3–0 victory and putting the defending champions within just nine points of league leaders Bayern.

[32] On 17 November 2010, in a friendly match against Ivory Coast, Błaszczykowski made his debut as captain of the Poland national team.

[33] On 8 June 2012, in the opening game of UEFA Euro 2012 against Greece, Błaszczykowski assisted Robert Lewandowski's goal in a 1–1 draw.

His first two strikes were from the penalty spot, his first gave Poland an early lead in their opening group game with Montenegro, a match which finished 2–2.

[38] On 12 June, Poland's opening game, Błaszczykowski played a key role in providing a cross and assisting in Arkadiusz Milik's goal in a 1–0 win over Northern Ireland.

Błaszczykowski also played in a goalless draw against Germany, but was dropped to the bench for the final group game against Ukraine.

[40] Błaszczykowski was selected for the final 23-man Poland squad for the 2018 FIFA World Cup,[41] but played only in the first game, a 2–1 defeat to Senegal in which he came off as a substitute at half-time.

[citation needed] Błaszczykowski scored on his record-breaking 103rd Poland cap, a 3–2 defeat to Portugal in the 2018–19 UEFA Nations League.

[42] On 16 June 2023, almost four years after his last call-up in the team, Błaszczykowski was called up for a friendly match against Germany at National Stadium.

He is a devout Catholic who reads the Bible on a daily basis, prays often, and participates in the Nie wstydzę się Jezusa (Polish for "I am not ashamed of Jesus") project.

[51] On 7 September 2024, a special Borussia Dortmund legends farewell match was held in order to pay tribute to Błaszczykowski and his compatriot Łukasz Piszczek who helped shape some of the most successful years in the club's history between 2010 and 2015.

The match was overseen by former club coach Jürgen Klopp and attracted over 81,000 spectators at the Signal Iduna Park.