The statuesque centre, who gained two caps on Ireland's 2005 summer tour to Japan, has been troubled by a shoulder injury this season, which has severely limited his game time at Northampton. He made 35 appearances for the club - scoring three tries - during his two-year stint at Franklin's Gardens.
The news comes as a considerable blow for the Saints who are busily preparing for their Heineken Cup semi-final against Wasps on Sunday. Quinlan's retirement comes just four days after the Saints' England-capped hooker Steve Thompson revealed his decision to quit rugby due to ongoing neck injury.
In a statement released today, Quinlan said: "It was my firm intention to see out the remaining year of my contract. And it is with great regret that I have had to end my career in this way.
"Rugby has been a massive part of my life for many years, and I am going to miss it greatly.
"It's been a wonderful couple of years at Franklin's Gardens. I have loved playing for the Saints with some great guys and under some great coaches.
"I hope to contribute what I can for the remainder of the season to ensure there will be Premiership rugby at the Gardens next season and European success this year."
The holder of a law degree from UCD and a masters in criminology from Cambridge University, the 29-year-old Quinlan certainly has the attributes to be a success off the rugby field. He gained his grounding in rugby at Blackrock College where he won two Leinster Schools Senior Cup medals.
Capped on the Ireland Schools team's tour to Australia in 1996, the Dubliner went on to play for his country at Under-19, Under-21, 'A' and senior levels. Notably, he played for Cambridge in the 2000 Varsity match and went on to play 50 times for Leinster between August 2002 and May 2005.
A bustling inside centre, he made his Ireland 'A' debut against Scotland in February 2003 and won his first senior cap as a replacement in the first Test against Japan in Osaka in June 2005. A week later in the second Test in Tokyo, he started at number 12 in a centre partnership with Gavin Duffy.
Commenting on Quinlan's decision to retire, Northampton coach Paul Grayson said: "We are disappointed to lose a player of his quality. It is a cruel way for his career to finish this way.
"He put his body on the line time and again for the club. We are losing a leader as well as a well-liked member of the squad."
- Everyone at the IRFU and IrishRugby.ie wishes David the very best of luck for the future -