Armstrong Inya Echezolachuku Oko-Flex (born 2 March 2002) is an Irish professional footballer who plays as a winger for Swiss Super League club FC Zürich and the Republic of Ireland under-21 national team.

[6] On 15 December 2021, Oko-Flex was an unused substitute for West Ham's Premier League fixture at the Emirates Stadium, a match won 2–0 by Arsenal.

Oko-Flex made his debut for West Ham United on 25 August 2022 coming on as an 82nd minute substitute for Manuel Lanzini in a 3–0 away win against Viborg in the second leg of a play-off round game in the 2022–23 UEFA Europa Conference League.

He made one first team appearance, in the UEFA Europa Conference League Play-Off round and featured on 35 occasions for the U21 side scoring 14 goals.

[16][17] Oko-Flex made his Republic of Ireland U21 debut on 16 June 2023, in a 2–2 draw with Ukraine U21 in a friendly played in Bad Blumau, Austria.