The Germany international posted a 15 second long video along with a caption thanking the club, its players, coaching staff and the fans for his time in London.
“Over the last 3 years I’ve had the pleasure of working with some amazing people at Arsenal, I want to thank everyone from all the staff behind the scenes to the manager & my team mates, who have all helped make London a second home to me.
“To the fans… The best fans in England, who have supported myself and the team no matter what, you will forever hold a special place in my heart and I will forever be a Gunner! I am confident that next season the team will be challenging for that league title and I will be watching on as a fan! COYG…”
Podolski joined Arsenal back in 2012 for £8 million from the Bundesliga side Koln.
The 30-year-old Germany international signed a three-year contract with Galatasaray earlier this week. The signing was unveiled by Galatasaray president Dursun Ozbek at the Ali Sami Yen Medya Center.
The 30-year-old won the World Cup with Germany last season and wants regular first team football to keep his place in the national team side.
Podolski scored three goals in 12 appearances for Arsenal last season. The Arsenal forward has scored 48 goals in a 125 international appearances.