Following the departure of Micky Adams in September, Page was put in temporary charge before being offered the job on a permanent basis until the end of the season.
The 40-year-old former Wales international defender has now put pen to paper on a deal to remain at the helm until 2017.
Vale chairman Norman Smurthwaite said: “I’m really pleased to be able to announce that Rob has signed a new contract to remain as manager of the club.
“I’ve been very impressed with how he has performed in the role so far and I am looking forward to seeing the team develop under his leadership.”
Page added: “I’m extremely proud to have agreed a deal to remain as manager of this great football club.
“I’d like to thank the chairman, the players and the fans for their support since I took over and I’m looking forward to building on what we have already achieved next season and beyond.”
Page joined Vale in 2011 as a youth-team coach and made his way up the ranks to the position of assistant manager to Adams.