Kelly’s registration has been completed in time for him to feature in tomorrow’s game away at Kidderminster Harriers.
Twenty-year-old Kelly, who has represented Ireland at under-18 and under-19 level, started his career rising through the academy at Sheffield United.
He spent time on loan with then-National League North side Stalybridge Celtic before joining Port Vale in June 2017.
He also had a ten-game period on loan at Port`s league rivals Bradford Park Avenue earlier this season.