The 18-year old beat Southampton's Alex Oxlade-Chamberlain and MK Dons' George Baldock to win the honour at a ceremony at The Brewery, London.
Jennings, in his first season as a professional after joining Rovers at the age of 16, has scored five times in 21 league appearances this term.
Parry said: "The award is a great achievement for Dale and it goes to show the hard work he has put in over the last two years. He deserves to be congratulated on it.
"I think it also reflects on what a fantastic job our youth department do. The award is about development. It is about taking in someone - in Dale's case about two years ago - and working on the raw material.
"It's not just about working on the boy's football ability, it is on the social skills side and education side as well."