Jenkins – regarded as one of the brightest young prospects in Welsh rugby – has impressed throughout the current season with a number of eye-catching displays.
The 22-year-old – who captained Wales Under 20s to the runners-up spot in the Junior World Championships in France in 2013 – has made a total of 49 appearances for Cardiff Blues.
Head Coach Danny Wilson said: “Ellis has produced some fantastic rugby this season and continues to improve as a player.
“He is a local lad who has come through the system at Cardiff Blues and wants to be part of what we are building here over the coming years.
“There is a huge amount of competition for places in our back row. It is testament to Ellis and his attitude that he wants to prove himself here and work in that kind of challenging environment.
“I first recognised his undoubted talent when I worked with him for Wales Under-20s and so I am thrilled that Ellis is not only part of the squad here and we have now secured his long-term future.”
Jenkins played for all the Cardiff Blues age grades and won the Welsh Championship every year he was in the squad. His performances saw him promoted to captain the Cardiff Blues Under-18 squad and then on to Wales.
He was integral to the Under-20 Junior World Cup team in South Africa in 2011/12, that were the first team to beat New Zealand at that level, earning a spot in the semi-final.
“I have been at Cardiff Blues since I was 15-years-old and this is where I want to play my rugby under the guidance of Danny Wilson,” he said.
“I worked with Danny in the Wales Under-20s set-up and know what a success he was there. I believe that’s where we are going and what we can build at Cardiff Blues given time.
“I have spoken to Danny about his long-term plans and I know the calibre of signings he also wants to bring in to take us forward.
“I enjoy playing for Cardiff Blues, have a great relationship with the fans and I feel this season I have also really stepped up my performances.
“I’m disappointed to not be playing right not because of injury, but I’m looking forward to getting back out there as soon as possible.
“It would have been easy to get up and move on,” he added. “We have players like Sam Warburton, Josh Navidi and Josh Turnbull in the back row so you are never guaranteed a jersey here.
“But I’m not that kind of person. I have confidence in my ability and to be able to challenge them. They would say exactly the same thing; we all push each other to get better.
“It has been a strange season in many ways for us. We’ve played some great rugby in almost every game, against the four Irish teams away at the start of the season we were in all the fixtures and could have got more.
“We just need to be more clinical and now turn performances into wins. In the last two games against Connacht and Montpellier we have shown the potential and hopefully we can now build on that.”
