The 23-year-old brother of Wakefield back-row forward James has signed a three-year contract with Saints and will link up with his new team-mates ahead of the 2019 season.
Batchelor played for Sheffield Eagles’ academy before having a year in Australia and also had a spell with Coventry before joining York in 2017 and catching the eye of a host of scouts with his impressive performances in League 1.
“Joe is a player we have had our eyes on this season,” St Helens coach Justin Holbrook said.
“He has been a real standout in Betfred League 1 this year and has been very consistent for a competitive York side.
“He is a strong running second rower with good skill and he also has a great work ethic. He has now matured as a player and hopefully he will continue to improve with us at Saints.
“We are looking forward to welcoming him into our system.”
Batchelor said: “I’m delighted to have signed with St Helens from next season and have the unbelievable opportunity to train in a full-time environment with world-class players and hopefully play Super League rugby.
“I am still 100 per cent committed to finishing my year at York and making sure it ends with promotion to the Championship.”