Jenkins, who is Wales’ most-capped international is the region’s current captain and has made 11 appearances this season. He will now enter his fourteenth campaign at Cardiff Arms Park.
He is delighted to agree a new contract and insists he still has plenty to give as the Blues enter a new era under the guidance of incoming head coach John Mulvihill.
Jenkins said: “I’m happy to sign a new deal with Cardiff Blues. I have been here for virtually all of my career and I’m enjoying captaining the boys and driving standards within the group.
“Moving away was never really an option for me so it is good to get it done and stay at the Arms Park.
“There is a great feeling a team spirit around the place at the moment and I really want to remain part of that.
“I’ve been pleased with my form since returning from a couple of injuries at the beginning of the season and feel I can continue to make a strong contribution on and off the pitch.
“I have had good conversations with John Mulvihill, who will succeed Danny Wilson in the summer, and I’m looking forward to next season.
“A continuing part of my role and responsibility here is to help develop some of the exciting front-row talent we have here, while competing for places.
“There is still plenty to play for this season and I am determined to finish the season on a high by qualifying for the European Champions Cup and going as far as we can in Challenge Cup.”
Throughout his Cardiff Blues career, Jenkins has made 193 appearances, scoring eight tries. He was part of both the EDF Energy Cup and Amlin Challenge Cup-winning sides and won the Heineken Cup with Toulon, during his one season away.
On the international stage, Jenkins has now amassed 134 caps, including selection on three British & Irish Lions tours.
Cardiff Blues chief executive Richard Holland added: “Gethin is an important member of the Cardiff Blues squad, is an outstanding professional and has a wealth of experience
“His recent form has proved he still has plenty to offer and he has an important role here both on the pitch as a player but also an experienced leader within the environment.
“He has spoken to John Mulvihill on a number of occasions and he has been impressed with both his form and leadership within the group.”