Reed is a product of the Southampton Academy who has represented England at the Under-19 and Under-20 level.

He made his Saints debut in the League Cup against Barnsley in 2013, coming off the bench in a 5-1 victory. He made his Premier League debut against Manchester City the same season, and his first start came a year later in a 3-0 triumph over Everton.

Reed joined Fulham on a permanent deal  on 30 August 2020 until the summer of 2024, with an option to extend by another year. He scored his first goal for Fulham in a 3-2 victory over Nottingham Forest at the City Ground on September 16, 2022.