Grzegorz Tomasiewicz

Youth career

He started his career in Szczakowianka Jaworzno, then in 2007, he started playing in MCKiS Sokół Jaworzno. In 2009, he joined Ruch Chorzów's youth teams. In 2011, he moved to Legia Warsaw's academy, the final club of his youth career.

Legia Warsaw II

In August 2013, he started playing for Legia Warsaw II, where he debuted eleven days later in a 1–0 III liga win over GKS Bełchatów II. He scored his first goal for Legia II in a 0–1 away victory over Broń Radom on 31 October 2013.

Arka Gdynia

On 13 February 2015, his transfer to Arka was announced. He made his I liga debut for Arka Gdynia in a 0–1 away defeat to Bytovia Bytów on 9 May 2015. He recorded his first goal for the club in a 0–1 away win over Chojniczanka Chojnice on 2 November 2015. Arka finished the 2015–16 I liga as champions, and were promoted to the Ekstraklasa.

Loan to Pogoń Siedlce

On 13 July 2016, Tomasiewicz was loaned to Pogoń Siedlce. He debuted in a 3–0 Polish Cup win against Stilon Gorzów Wielkopolski, where he scored the first goal in Pogoń. Tomasiewicz made his first league appearance for Pogoń on 31 July 2016, in a 0–1 away win at GKS Tychy. He scored his first I liga goal for the club in a 2–1 victory over Chojniczanka Chojnice on 23 September 2016.

Piast Gliwice

In 2022, Tomasiewicz was transferred from Stal Mielec to Piast Gliwice.

Śląsk Wrocław

On 11 June 2026, newly promoted Śląsk Wrocław announced the signing of Tomasiewicz…

Arka Gdynia

I liga: 2015–16 Stal Mielec

I liga: 2019–20