The Poland winger has joined Inter in a Bosman deal from Napoli, penning a deal to 2028.
“I am very happy because I am joining one of the best clubs in the world. It is an honour for me, I can’t wait to get started,” Zielinski told the official Inter channel.
“The Inter midfield is truly the strength of this team, so I will try to give my contribution to make the side even stronger.
“They were always tough games against Inter, a well-organised team with so much quality. They press really well, as soon as they lose the ball, they are ready to be aggressive and win it back. This was the key, along with the general quality of the squad.
“I’ve been in Italy for 12 years and I am very happy to continue my career here. I am the first Poland international to wear this prestigious jersey and will try to do my best to achieve great results.”
The 30 year-old added: “I will give everything to make the Inter fans happy. The stadium is wonderful, one of the most beautiful in Italy. I’ll do all I can to show my quality and bring more trophies to the club.”