On 28 January 2022, Charlsey joined League Two side Port Vale for an undisclosed fee. Manager Darrell Clarke had looked to strengthen the midfield department after injuries to Tom Conlon and Jake Taylor. Charlsey was part of a midfield three of Tom Pett and Ben Garrity that helped the "Valiants" to put together a winning run in March. He scored his first goal for the "Valiants" on 5 April, to secure a 1–0 victory at Salford City. He played as a substitute in the play-off final at Wembley Stadium as Vale secured promotion with a 3–0 victory over Mansfield Town; Michael Baggaley of The Sentinel wrote that "[Charsley put in] a typically dynamic performance against his old club". He made ten appearances in the first half of the 2022–23 season, but left the club by mutual consent in January 2023 after securing a deal elsewhere;director of football David Flitcroft said that "Harry's ability in training has been high, but due to the competition in front of him the minutes on the pitch haven't been available".
