The 19-year-old is currently on loan at the club and scored his first Rovers try in Friday night’s 32-12 victory away to Sheffield Eagles.
Whylie, who is sponsored by Ward Hygiene Services, will join Featherstone on a one-year deal.
He said: “I’m really buzzed to be here for a full season and I can’t wait until those games start.
“I’m really enjoying myself here, competing at a really good standard.
“I have set myself goals to achieve and Featherstone is a place where I can do that.
“It felt really good to get my first try on Friday night and I’m sure there will be more to come.”
The recruitment of Whylie follows the additions of Papua New Guinea Internationals Watson Boas and Ase Boas, as well as local youngster Morgan Punchard.
Rovers general manager Davide Longo said: “We are delighted that Dakota has signed for us.
“He’s already shown that he can handle the Championship at the highest level, with his debut performance against Toronto and subsequent games thereafter.
“He’s been nurtured in a fantastic environment at Leeds Rhinos and credit must be given to Jonny Wainhouse and Rob Burrow (Leeds Rhinos under 19s coaches), who’ve supported both Featherstone Rovers and Dakota, throughout his time with us.”