Fish will spend the remainder of the season with the Hibees, who are eighth in the table with five points from five games.
It's the 19-year-old's second temporary move away from the club, as he played his football during the first half of 2021/22 out on loan with Stockport County.
Will, who has captained both our Under-21s and Under-18s sides, has made one senior appearance for the club so far.
The defender replaced Dan James in the closing stages of the 2-1 win at Wolves on the final day of the 2020/21 season.
He also travelled with the squad on this summer's pre-season tour, appearing in the 3-1 win over Crystal Palace at the MCG.