The 30-year-old began his career at hometown club St Helens 11 years ago and also played for Salford Red Devils and Bradford Bulls before joining Giants in 2017.
Gaskell, who can play at full-back, centre and half-back, said: "I'm really looking forward to joining Wakefield next year and the challenge it's going to bring.
"I think they've got a really exciting squad there and I'm looking forward to playing with them.
"They play a way which excites me, and I see myself as an attacking threat, whether that be half-back, full-back or any other position.
"I like to throw the ball about and the way they play, I think, will suit my style.
Gaskell added: ""There's some real good competition for places at Wakefield and any good team needs that.
"Max Jowitt, at full-back, is a terrific player and the halves in Jacob Miller and Mason Lino are quality too.
"We'll all be pushing each other next year and I'm looking forward to working with those type of players.
"I had a really good chat with [coach] Chris Chester and he really sold the club to me.
"He made it clear the club were really keen to bring me in and I'm now just excited to see where we can go."
Chester, whose Wakefield contract expires this autumn, reckons Gaskell will be a major addition to Trinity's squad.
"I'm really pleased to sign a player of Lee Gaskell s quality," he said.
"He has proved over the years he is a quality Super League player and his form in 2021 has been superb.
"Lee will add some quality to our backline and his versatility is valuable too, with his ability to slot in at full-back, half-back and centre easily."
A decision has yet to be announced on Chester's future, but he dropped a possible hint by adding: "I'm excited to see Lee in the red, white blue in 2022 and really looking forward to working with him."
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