Białkowski began his career playing in Poland, before moving to Southampton in 2006. He spent 6 years there, and was loaned out to Ipswich Town and Barnsley during that time, before joining Notts County where he spent two seasons. moved to Ipswich Town in 2014 and spent a further 6 years with them, with a season-long loan to Millwall in 2019/2020. He finally joined Millwall on a permanent transfer in 2020. Białkowski has also represented his country at international level, making his senior debut for Poland on 23rd March 2018 in a friendly against Nigeria, coming on as a substitute for Łukasz Fabiański.