The highly rated 17-year-old has penned a three-year deal with the Club, having previously been on the books at Arsenal.
Making her senior debut for the Gunners in September 2020, she gained further first team experience during a dual registration spell at Birmingham City towards the end of the Women's Super League season.
In total, Mace featured eleven times in total for the Blues as Carla Ward's side successfully staved off relegation.
A versatile player, Mace is capable of operating at the heart of the defence or in a midfield role and has featured for England at youth level.
While she's admitted that leaving Arsenal was a difficult decision, her excitement at joining Gareth Taylor's side is also clear to see.
The young defender was all smiles as she was unveiled in a City shirt, and can't wait to start the latest chapter of her nascent footballing career.
Enjoy the best pictures from Ruby Mace's signing via the gallery below...