The centre, who scored a match-winning last-minute try against Glasgow in December, has committed himself to his hometown club until 2020.
The 23-year-old former Scotland Sevens and youth international has scored five tries in 17 appearances this season.
Dean said: “I’m delighted to be staying in Edinburgh for another two years. I’m loving my rugby at the moment and I’m thoroughly enjoying being a part of where this club is going.
“I’m excited to carry on improving under Richard Cockerill and will be looking to put my best foot forward for the club and the squad in the years to come.”
Head coach Cockerill added: “We’re delighted that Chris has chosen to extend his stay in Edinburgh. He’s been one of our most consistent performers this season and is central to the club’s plans moving forward.
“Chris is a young, talented player and he’s only going to improve in the years to come.”