Gabriel Jesus, 25, has signed "a long-term contract", the London club said in a statement without giving further details.
The amount of the transfer is estimated by the British press at 45 million pounds (52.3 M EUR).
"We are delighted to have signed a player of the caliber of Gabriel Jesus (...) He is 25 years old, he is a confirmed Brazilian international who consistently shows that he is a high quality player", indicated his compatriot Edu, sporting director of Arsenal.
Since arriving in England in January 2017, the former Palmeiras striker has won eleven trophies, including four Premier League titles.
He played 236 matches for City and scored 95 goals.
"It was a pleasure to play for City," explained Gabriel Jesus in the press release from the Mancunian club.
"I feel like I've become a better player since I arrived and winning all those trophies has been amazing," he added.
Manchester City, who have recruited Norwegian prodigy Erling Haaland, are also on the verge of parting with England international striker Raheem Sterling, announced by the British press leaving for Chelsea.
© 2022 AFP