Kowalski started his career with Polish side
Jagiellonia Białystok. On 16 July 2022, he made his senior debut as an injury-time substitute in a 2–0
league win over
Piast Gliwice, and scored his first goal for the club less than a minute after entering the pitch. On 31 January 2023, Kowalski was transferred to Italian
Serie B club
Parma for a reported fee of €1 million. His first competitive senior team appearance came on 11 August 2024, in a 0–1
Coppa Italia first round loss to
Palermo. On 31 August, Kowalski made his first
league appearance and start for Parma in a 1–2 defeat against
Napoli. Shortly after, in September 2024, he
tore his ACL while training with the
Poland's under-20 team. After recovering, Kowalski was sent on a season-long loan to Portuguese side
Torreense in August 2025. On 5 February 2026, he moved on loan to
I liga club
Miedź Legnica, with an option to buy, for the rest of the season. ==International career==