Hock, who arrived at the LD Nutrition Stadium in January following a spell with Leigh Centurions in Super League, has scored three tries in 14 appearances for Featherstone.
The ex-Wigan Warriors forward overcame a knee injury prior to making his Rovers debut and is delighted to be extending his stay with the club.
Hock said: “I am over the moon to have signed for Featherstone for another year, it is fantastic to be staying with such a great club.
“I have loved every minute of my time here so far, despite it taking me a bit of time to get going due to the injuries I suffered last year.
“I feel fit now, though, and am improving with every game.
“The fans have been superb and I cannot wait to rip in for the rest of this season and next.
“We want to nail our place in the top four and have a good go in the Qualifiers.”
Rovers head coach John Duffy added: “Gareth has been great and has really bought in to what we are trying to achieve.
“It has been fantastic to have him around the club and he is getting better every time he steps onto the field. He is a born winner. He leads by example in everything he does and is very popular with the players and staff. With a full pre-season under his belt, Gareth will only get better.
“He is focused on finishing this season on a high and he knows where we want to be.”