Sharman, 23, makes the move to Ingfield from fellow NPL East Division side Pontefract Collieries.
The young defender began his career at Chesterfield, before enjoying time on loan with Dover Athletic, Kidderminster Harriers and Blyth Spartans.
Following his release from the Spirerites, Sharman joined Matlock Town in 2021, going on to make 82 appearances for the Gladiators, winning Young Player of the Year, among various accolades.
He joined Bradford (Park Avenue) in January 2024, before departing to Pontefract a month later.
On his new signing, Ossett United manager Dave Wild said: "I can’t underestimate how pleased I am that Jamie has agreed to join us at Ossett.
"I’ve worked with Sharmo during my time at Matlock Town and he completely epitomises the values that I place within our sides.
"He’s a no-nonsense defender with a wealth of non-league experience to his name, and the standards he will bring to our squad is exactly what we need.
"I don’t want to overcook it and place pressure on Jamie but I really do feel that this is the final piece of the defensive structure that we want allowing us to be a fluid in changing systems if needs be.
"I think the fans will very quickly understand that Jamie is a top-drawer defender and I really am looking forward to observing his progress at the club and higher up the non-league ladder going forward."
Wild's revolution at the Sheepicorns continues with the addition of Prince Haywood.
The Ghanaian-born midfielder has a wealth of experience in the Northern Premier League from his time at the likes of Stalybridge Celtic, Witton Albion, Nantwich Town and Radcliffe.
On his move to West Yorkshire outfit, Haywood said: "David [Wild] was a big reason I signed on, he’s been trying to sign me for the past few years.
"Now that I have moved to Wakefield it was a no-brainer to finally join him and to help him take this club where it belongs.
"I’m ready to put in the work and show them why David brought me to the club."
Manager David Wild added: "I’m really pleased to have the opportunity to work with Prince.
"He’s a player I’ve tried to sign at pretty much every club I’ve worked at with the timing and location of Prince this time round has all fallen into place.
"He is a fantastic footballer, who does the basics of the game in midfield better than most I’ve seen.
"He’s a tenacious, hardworking winner and I know he will quickly become a fan favourite within the club.
"Prince has a wealth of experience at NPL levels including promotions so his willingness to win, experience and style of play made the decision to get him into the club an easy one."
Ossett United have also confirmed the signing of goalkeeper Ally Hughes.
The young shot-stopper, who has spent time at West Chorlton & Didsbury and Vauxhall Motors, will replace the outgoing number one Callum Hiddleston, who announced that he will be taking up another opportunity elsewhere.
On the signing of Hughes, Wild said: "Ally has a huge future ahead of him in non-league football and I’m glad he has chosen us to work with for the coming years despite offers from elsewhere.
"He has exceptional distribution and on top of that has a presence that is both commanding and no-nonsense which is an absolute must for me with goalkeepers.
"I was lucky enough to work with Phillo [Paul Phillips] for a long time who for me is one of the best goals keepers non-league has ever had and his mindset on keepers have become a staple point for how I want my sides to be protected and Ally absolutely fits that glove.
"As with all the new signings I’m sure that everyone will welcome Ally to the club with open arms and support him throughout
"It is important that I give a special mention to Leon Osborne on this deal too who’s worked tirelessly whilst I’ve had work commitments."
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