The 21 year old joins after a season at Toulouse Olympique, where he made two appearances in 2024.
Walsh came through the academy system at Wakefield Trinity, where he was coached by Knights’ boss, Mark Applegarth, before moving to study at Newcastle University.
From there, he joined Newcastle Thunder in 2023, making nine appearances for Chris Thorman’s side.
After signing for Hunslet for 2024, he earned a trial with a view to a full time contract with the French club.
He spent time on loan last season at Whitehaven, playing seven times for the Cumbrians including in the 40-0 defeat by York Knights.
Applegarth said: “I'm really glad we’ve got Mac on board. It gives us a bit more depth in those wing and centre positions.
“He’s a kid I’ve coached before at Wakefield in the Academy. Things didn’t go his way last year, he didn’t play play too much.
“He’s looking for an opportunity, so if he trains hard and puts his best foot forward he’ll definitely get that at York.
“I'm glad we’ve got him on board and I’m looking forward to linking up with him again.”
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