The youngster will initially join up with the Hammers under-23 squad.
West Ham have completed the signing of Ireland under-19 international Armstrong Oko-Flex on a two-year deal, with an option for an additional year.
Armstrong Oko-Flex made two senior appearances Celtic throughout 2020/21 before the expiration of his contract at the end of the season. Oko-Flex will join fellow Ireland underage internationals Ademipo Odubeko and Conor Coventry at the London Stadium.
Armstrong Oko-Flex has represented both England and Ireland
Born in Dublin to Nigerian parents, the promising winger was scouted by Liam Brady for Arsenal at the age of 11, while playing for St. Kevin’s Boys in Dublin. He then moved to Celtic in 2018 and made his senior debut as a substitute against Hibernian in January of this year.
Oko-Flex has represented both England and the Republic of Ireland at youth level, with England previously reported to have been keen on getting him to commit to the Three Lions.
Armstrong Oko-Flex could feature in Europa League campaign
Speaking to the West Ham United website, the youngster said: “I feel very good to have signed. It’s good to sign for a big club like West Ham United.
“I’m very excited to get started here. There are a lot of positives around West Ham and it’s just a great club to be at right now.
“I know a lot of the boys here already. I trained with some of them when I was younger, and I’ve played against some of them as well, so it’s been good settling in and the coaches have welcomed me in very nicely as well.”
Described as “skillful, quick and sharp in front of goal,” the Dubliner had a brief trial at West Ham at the end of last season and will initially link up with their under 23s squad. However, with the East London side competing in the Europa League in the upcoming campaign, there could be some opportunities for him to impress Hammers boss David Moyes.