Krystian Bielik (pronounced , born 4 January 1998) is a Polish professional footballer who plays as a centre back or defensive midfielder for Premier League club Arsenal and Poland U21's.
He first played senior football with Legia Warsaw in 2014, spent the second half of the 2016–17 season on loan at EFL Championship club Birmingham City, and spent the 2018–19 season on loan at Charlton Athletic, helping them gain promotion from League One. Internationally, he has represented Poland up to under-21 level.
Bielik started playing football for his hometown club, Górnik Konin before being spotted by Lech Poznań scouts in 2012, and later joining their developmental academy. He won the Polish U-17 Championships with the club in early 2014. However, in July 2014, Bielik joined Lech's archrivals, Legia Warszawa for 50,000 zł (£9,000), and on 24 August, he made his Ekstraklasa debut against Korona Kielce.