Nat Phillips was born on 21 March 1997 in Bolton, Greater Manchester. He came through Bolton Wanderers' academy before joining Liverpool's setup in 2016, having turned down a university scholarship in the United States just two days before his planned departure. His path to first-team football was gradual, including loan spells at German second-division side VfB Stuttgart, where he made his professional debut in 2019.
Phillips earned his Liverpool league debut in October 2020, starting in a 2–1 win over West Ham United. His most notable moment in a Liverpool shirt came in March 2021, when he delivered a man-of-the-match display in a 2–0 Champions League victory over RB Leipzig, helping the side advance 4–0 on aggregate. He also scored his only Liverpool goal in a 3–0 win at Burnley in May 2021.
A composed, aerial-dominant centre-back, Phillips spent subsequent seasons on loan at AFC Bournemouth, Celtic, Cardiff City and Derby County, accumulating Championship and European experience. His 33-game stint at Derby in 2024–25 was particularly productive, helping the club avoid relegation under head coach John Eustace.
In June 2025, Phillips made a permanent move to West Bromwich Albion, signing a three-year contract with the Championship club. At West Brom, he is expected to be a regular presence in the heart of defence as the club builds its squad.