Arthur Okonkwo was born on 9 September 2001 in Camden, London, to Igbo Nigerian parents. He joined the Arsenal academy at the age of eight and progressed steadily through the youth ranks, signing his first senior contract with the club in July 2021. He made his senior debut shortly after, in a pre-season friendly against Hibernian.
Unable to break into Arsenal's first team, Okonkwo developed his game through a series of loan spells. At Crewe Alexandra in League Two during 2022–23, he made 26 appearances and kept ten clean sheets before being recalled. He then joined Austrian side Sturm Graz, where he played in the Austrian Cup final as Sturm beat SK Rapid Wien 2–0 to claim the trophy. His most sustained run of form came during two seasons on loan — and then permanently — at Wrexham, where he made 40 appearances in his first campaign, kept 16 clean sheets, and was named in the EFL League Two Team of the Season for 2023–24.
A composed shot-stopper with an eye for the spectacular, Okonkwo has cited Petr Cech and David De Gea as influences on his style. He left Arsenal on a free transfer in June 2024 and signed a three-year deal with Wrexham, where he is now the club's first-choice goalkeeper as they compete in the Championship.
Internally represented England at youth level, Okonkwo has since switched his international allegiance to Nigeria, with FIFA confirming the change in April 2026.