Harries signed for Forest Green in January 2025 on a permanent deal from National League side, Woking.
The central defender joined Woking at the start of the National League 2024/25 season following his release from Aldershot Town, making 29 appearances in all competitions.
The Swansea City and Wales youth product is another player familiar with the southwest having had a loan spell with Cheltenham Town before donning the shirt for Bristol Rovers and Swindon Town.
Harris also has experience abroad having played in the Netherlands for Eredivisie side, Fortuna Sittard where he made 9 appearances, scoring once, at the beginning of the 2019/20 season.