Stuart Gallacher, Chief Executive of the Llanelli Scarlets said: "I can't think of a better person to take up the reins from Ray Gravell who was such an dedicated and enthusiastic president.
"Derek is a hugely respected figure in the game of rugby not only in Wales but worldwide and I know he will be a great support to the Scarlets at a crucial time in our history.
"To follow in the footsteps of someone like Ray Gravell is not easy, it will take a certain gravitas and Derek is in all senses, a true rugby statesman.
"The President of Llanelli RFC is an important link between our tradition and our future as a rugby region and equally between our supporters and our rugby business.
"I know he will be a great ambassador for us on the local, national and international stage with his long-established connections with The Lions and The Barbarians."
Derek Quinnell said: "Grav was a natural President and these are big shoes to step into, however I am really looking forward to it. I am very keen to make a contribution to the future of rugby in the region and I will help in any way I can.
"These are certainly exciting times; we have a magnificent new stadium and a new look coaching team so we have plenty to look forward to. There is a great deal of anticipation amongst our supporters as we move into a new era.
"Leaving Stradey Park will be a wrench but it is also an exciting one. We will all celebrate the long history of the club as Stradey Park closes but the road now leads to Parc y Scarlets. The key will be producing results on the field at Parc y Scarlets to encourage even more people through the gates."
Quinnell was born in Llanelli in 1949. He won 23 Wales caps as a lock-forward and No8. He first played for Llanelli RFC in 1967 and made his international debut for Wales against France in 1972. He captained Llanelli in 1979-80 and went on three British and Irish Lions tours. His first Lions tour was in 1971 against New Zealand and was the only player in the squad not to have been capped by his country. All three of his sons, Scott, Craig and Gavin have played top-flight professional rugby.
Llanelli RFC Association was formed after the club become incorporated 12 years ago. It has its own constitution, a membership and is wholly owned by group company Llanelli RFC Ltd (which owns the Llanelli Scarlets and Llanelli RFC). The Association nominates two heritage directors to sit on the board of Llanelli RFC Ltd- these are currently Marlston Morgan and Hefin Jenkins.