Filonczyk studied at the Academy of Music in Wroclaw with Bogdan Makal. He was a member of the Young Talents Development Programme at Polish National Opera (under Eytan Pessen). He made his debut at Teatr Wielki, Poznan, in 2015 as Tonio Pagliacci and has since returned there to sing Andrey Shchelkalov Boris Godunov and Eugene Onegin. Engagements elsewhere include Marcello for Canadian Opera Company, Figaro Il barbiere di Siviglia for the Bolshoi, Frank/Fritz Die tote Stadt for Bavarian State Opera, Silvio for Teatro Regio, Turin, Schaunard La Boheme for Teatro Lirico, Cagliari, and Cecil Maria Stuarda and Figaro Il barbiere di Siviglia for Zürich Opera House as a member of the International Opera Studio. He participated in the 2016 Salzburg Festival Young Singers Project, singing Gubetta Lucrezia Borgia.

Filonczyk’s awards first prize at the Ninth International Stanislaw Moniuszko Vocal Competition. His concert appearances include Fauré’s Requiem for Polish National Opera as part of the Szalone Dni Muzyki Festival.

Polish baritone Andrzej Filonczyk makes his Royal Opera debut in the 2017/18 Season as Silvio Pagliacci and returned as Schaunard La bohème. In the 2019/20 Season he sang Marcello La bohème.