He is on the books of Peterborough United and wears shirt number 23. His main role on the pitch is Defender. His stronger foot is Left. His estimated market valuation currently stands at 150K €.

His latest transfer saw him join Peterborough United from Enfield Town via Loan on 2024-10-31.

Across the English Football League One 2025-2026, Harley Mills appeared in 14 matches and averaged 1.4 tackles, 0.9 interceptions, 3.9 clearances, and 0.3 blocked shots per game.