The 22-year-old, who has been at Salford since he was 14, is enjoying his most prolific season in the first team having established himself in the side with two tries and six assists alongside 28 goals.
He is the third player to sign a contract extension since the arrival of new head coach Brian Noble, following the lead set by captain Martin Gleeson and Australian prop Shannan McPherson.
"I'm really pleased to have signed this extended deal," Sneyd said. "I have been at Salford a long time now and I want to be here while all this exciting stuff is going on.
"I want to be here when this team is hopefully reaching the play-offs every year and winning trophies."
- Sports & Recreation