The 31-year-old will quit north London when his contract expires on June 30, with a free-transfer return to former club Lyon his expected next destination.
Lacazette struck 71 goals in 206 appearances in five years at the Emirates Stadium outfit.
Arsenal have been heavily linked with a move for Manchester City’s Gabriel Jesus, and Lacazette’s departure opens up a berth in Mikel Arteta’s squad.
Gunners boss Arteta hailed Lacazette’s influence ahead of the France striker’s departure.
“Laca has been a fantastic player for us,” said Arteta.
“He’s been a real leader on and off the pitch and has been a very important influence to our younger players.
“His commitment with us has been exceptional and we wish him and his family success and happiness.”
Lacazette admitted the time had come for a new challenge.
“I’m looking forward to a new experience and a new adventure,” Lacazette told Arsenal’s official club website.
“I want to keep all the good moments I had in the club, because for me it was just a pleasure to play for a club that, since I was young, I dreamt of.
“I’m really happy to have played for five years for Arsenal.
“I’ll keep in contact with my team-mates, with the coaches, with the club.
“I supported Arsenal since I was young, so obviously I’m going to keep supporting them. I know I will come back to the stadium as well.”