The 2020–21 Widzew Łódź season was the club's first season back in I liga since promotion from II liga in 2020.

They competed in the season's Polish Cup edition, where they were eliminated by Legia Warsaw, following the 0–1 defeat in the round of 32.

[2] Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Players may hold more than one non-FIFA nationality.

In January 2021, Widzew Łódź faced Warta Poznań (1–3 defeat), Polonia Warsaw (2–1 victory) and Sokół Aleksandrów Łódzki (2–0 victory).