Reed was born in London and spent the first year of his life in England where his father was working.

[3] He played college baseball at Stanford and was the closer for the Cardinal in 2011, picking up 9 saves and a 6–2 record, with a 2.54 ERA in 28 games.

On November 20, 2014, he was added to the Dodgers 40 man roster in order to protect him from the Rule 5 Draft.

[10] He was assigned to the AA Tulsa Drillers to start the season, and also moved into the bullpen after having previously been a starter.

[14] He was assigned to the AAA New Orleans Zephyrs but the Marlins called him up to the majors for the first time on August 1.

[15] He pitched two scoreless innings of relief in his debut that night against the San Diego Padres.

On May 7, 2021, Reed signed with the Long Island Ducks of the Atlantic League of Professional Baseball.

[19] Reed was selected to represent Great Britain at the 2023 World Baseball Classic qualification.