Ayden Heaven was born in London and grew up supporting Arsenal, eventually joining the club's academy at the age of 13 in 2019 after earlier spells in West Ham United's youth setup. He earned a scholarship contract at Arsenal in 2023 and trained with the first team on occasion, attracting praise from manager Mikel Arteta during the 2024 pre-season alongside fellow youngsters Myles Lewis-Skelly and Ethan Nwaneri. He made his senior debut for Arsenal in the EFL Cup against Preston North End in October 2024, helping the club to a 3–0 win.
In February 2025, Heaven moved to Manchester United on a four-and-a-half-year deal. He has steadily established himself in the side, making his first Premier League start in March 2025 and recovering from an ankle injury to play a growing role. Notable moments at Old Trafford include assisting Bryan Mbeumo's goal in a 4–2 victory over Brighton in October 2025 and earning his first Premier League Player of the Match award in a 1–0 win over Newcastle United on Boxing Day 2025. He was part of the Manchester United squad that reached the UEFA Europa League final in 2024–25.
A naturally left-footed centre-back, Heaven is typically deployed on the left of a three-man defensive line, where he combines effective channel defending with composure in possession. Manchester United regard him as a long-term defensive option, reflected in the length of his contract.
At international level, Heaven has represented England at under-18, under-19, and under-20 level. He is also eligible to represent Ghana through a grandparent.