The 27-year-old, who scored four goals in a dozen appearances for the Pilgrims during a previous loan spell in 2020-2021, will be plying his trade at the Jakemans Community Stadium once again for the season ahead, subject to final ratification from the game's governing bodies.
United manager Craig Elliott was delighted to land his latest signing and said: "Joe has incredible stats in his career, producing a high number of assists and goals on a regular basis.
"You could see his confidence and fitness improve just before last season was stopped and he was proving to be a key player for us.
"Joe is a great lad in the dressing room and he's now coming into his peak years as a player, so I am really looking forward to working with him again.
"I also wish to thank Simon Weaver for his help in securing this deal for the season."
Leesley's imminent arrival takes United's squad to 17 members for season 2021-2022:
Jordan Burrow, Shane Byrne, Peter Crook, Connor Dimaio, Scott Duxbury, Scott Garner, Paul Green, Terry Hawkridge, Joe Leesley, Tom Platt, Fraser Preston, Jordan Preston, Jay Rollins, Luke Shiels, Andi Thanoj, Matt Tootle, Jake Wright.