9th November 2017, 13:24 | Castleford
The 22-year-old becomes the first player to take advantage of the new dual-registration agreement between the clubs.
Maher made just two appearances for the Tigers this year and spent much of the season on loan at Batley.
“His game time may be limited at Castleford next year and with us being a little light in the forwards, he will add to our young and vibrant pack for 2018,” said Fax head coach Richard Marshall, who worked with the forward during his time with England Academy.
“He is an intimidating figure and will be a huge addition to our go forward.”
Maher added: “I’m really looking forward to getting some consistent game time with Halifax and improving my game.
“The move will help me grow as a player and develop my career.”