The Welsh record cap holder has spent 11 years with the Blues during two spells and has made 173 appearances for the Blues.
Head coach Danny Wilson made the loose-head prop captain ahead of last season and he has retained the honour in 2016-17.
And as Jenkins enters a testimonial season, supported by both Cardiff Blues and the Welsh Rugby Union, he has penned a new deal.
Jenkins said: “I’m really pleased to have signed an extension with Cardiff Blues. Having spent 11 years of my career here it was an easy decision to make.
“I’m very optimistic about the future, we are building in the right direction, making progress and I’m looking forward to playing my part in that. I am also honoured to be captain for a second season and take immense pride at leading this team out.”
Jenkins made his regional debut in 2004 and was part of the Anglo-Welsh and Amlin Challenge Cup winning teams of 2008 and 2009. During his one-year stint with Toulon he also picked up the Heineken Cup.
The 35-year-old has also enjoyed an illustrious playing career with four Six Nations titles, including three Grand Slams, and three British & Irish Lions tours under his belt. And Wilson is confident Jenkins can add even more to his glittering CV.
Wilson said: “Gethin has been a standout loose-head prop for more than a decade and has been an unbelievable servant to Cardiff Blues.
“He is a fantastic professional, which has prolonged his career, and has been an instrumental leader for us in driving standards both on and off the pitch.
“Gethin still has a big future at Cardiff Blues and he proved during the Wales summer tour of New Zealand that he is still one of the best international loose-heads out there.
“With Gethin, Rhys Gill and a number of youngsters we have great depth in the position and that is exactly what we need throughout the squad.”
