Joshua Mason Akinwunmi was born in Birmingham, England. His mother is third-generation Trinidadian and Grenadian of Indian descent, and his father is first-generation British of Nigerian descent.

Josh's family relocated to Maresfield, East Sussex before his second birthday and Josh went on to attended Great Walstead School and Bedes School. Growing up, Josh was a keen football and rugby player. Aged 10, he underwent chest surgery to correct a congenital abnormality which temporarily prevented him from playing football and rugby, and led him to turn his focus to driving simulator games.

Aged 14, Josh began racing go-karts, taking part in club racing at Buckmore Park and PF International in the Junior Max (Rotax) and selected Junior X30 classes at the end of the 2016 and 2017 seasons. Although 14 would be considered an extremely late age to start karting, Josh made steady progress winning rookie trophies before making the step into car racing.

After a successful 2023 season in FIA Formula 2, Josh makes the move to INDY NXT by Firestone in 2024, joining Abel Motorsports in the No. 21 car.