The player was not offered a scholarship by the Gunners ahead of the 2019-2020 campaign.
Okoye attended Dagenham Park Church of England School and used to play for Sunday team Freestylers before he was recommended to The Gunners.
Playing as an attacking midfielder, Okoye was a member of the Arsenal U15 side at the prestigious Marveld Tournament in 2017.
Other members of the squad of Nigerian descent were England U17 star Miguel Azeez, Mazeed Ogungbo, Armstrong Oko-Flex, Ovie Ejeheri and Malcolm Ebiowei.
Azeez has already signed a scholarship with Arsenal, which will be activated on July 1 and will go professional after his seventeenth birthday in September.
Nigeria international Alex Iwobi, Kelechi Nwakali, Xavier Amaechi, Folarin Balogun, Tolaji Bola, Arthur Okonkwo, James Olayinka, Tobi Omole, Joseph Olowu, Bukayo Saka and Ryan Alebiosu have been retained for the upcoming season, according to allnigeriasoccer.com