The 34-year-old, who spent seven seasons at Juventus, had one year left on his contract, but is now available as a free agent and Italian media reports have linked him with Serie A club Monza and Al-Nassr of the Saudi Pro League.
"In an instant, Tek conquered the Juventus fans of the world and we are sure that we will all always carry in our hearts the man and the professional who wore our jersey with pride and commitment," Juventus said in a statement.
"Thank you for everything Tek and good luck for the future."
Szczesny began his career at Arsenal, joining the club at age 15 in 2006, before signing for Juventus in 2017 having had loan spells at Brentford and AS Roma.
At Juventus, where he made 252 appearances, Szczesny won three Serie A league titles and three Coppa Italia, and he has 84 caps for Poland. In July, Juventus signed keeper Michele Di Gregorio from Monza.