The 18-year-old has made two appearances for the first team so far, enjoying back-to-back outings against Livingston and Raith Rovers last season.
Earlier this term, the striker netted four times in 15 appearances on loan at East Stirlingshire and has impressed the Tynecastle coaching staff enough with his displays for the club’s under-20s to merit a fresh contract.
Roy said: “I’m really happy to sign a year’s extension.
“Hopefully I can progress further if I keep working hard and scoring goals.
“If that comes along, then hopefully I can get a chance in the first team.
“I’ve had a taste of that before and that’s what I’m aiming for again.
“Hopefully I can get back to that and make it a regular thing.
“It’s a very big year for me coming up.”