In a World Cup year, Leno is desperate for regular game time to get in the Germany squad for the competition this winter.
However, he could not hide the joy he has experienced at Arsenal in the past few years in his goodbye message.
"Hey Arsenal fans, it's time to move on for me," he tweeted.
"It's been a pleasure to be part of this great football club for 4 amazing years.
"Thank you very much for your support. Also a big thank you to my team mates and the staff behind the team. I'm looking forward to seeing you soon!"