Phillips, who quit the international game in 2015, won 94 caps for Wales and five for the Lions in what was a stellar career at the highest level.
He was part of the Wales sides which won Grand Slams in 2008 and 2012 and also secured Six Nations glory in 2013 with a famous 30-3 victory over England in Cardiff.
The 34-year-old, who played for three of Wales’ four regions – Scarlets, Cardiff Blues and Ospreys – is currently with English side Sale Sharks, but won’t play on past the end of the current campaign.
Phillips said: “I would like to announce my retirement as a professional rugby player at the end of this season with Sale Sharks.
“Thanks to the fans, team-mates, clubs, coaches, the Welsh Rugby Union and my friends and family who have supported me over the years.
“I will attack the next chapter with the same passion, commitment and laughter as I did during my entire career. See you soon!”
Phillips made his Wales debut against Romania in 2003 and had to regularly battle Dwayne Peel for the red scrum-half shirt.
After making the 2007 World Cup, the arrival of Warren Gatland as Wales head coach saw Phillips given a new lease of life and between 2008 and 2014 he was pretty much first choice.
Gatland was a big fan of his physicality, and he went on to become one of the world’s best exponents of the scrum-half art at the time.
In 2008 he helped Wales win a Six Nations Grand Slam and went on to play a starring role on the 2009 Lions tour of South Africa.
Phillips’ battle with Fourie du Preez in that series was an intriguing one and although the Lions came out on the wrong side of the result, the Welshman’s already burgeoning reputation was only enhanced further.
Further Six Nations titles in 2012 and 2013 saw Phillips at the centre of more Welsh success, and he went on a second Lions tour to Australia.
After failing to make Gatland’s initial squad for the 2015 World Cup – he was latter called up as an injury replacement for Rhys Webb – Phillips retired from international rugby in December of that year.
His club career, which also saw him play for French sides Bayonne and Racing 92, took him to Sale where he has played alongside old rival Peter Stringer.
That will end come the conclusion of this season, but Phillips will always be remembered as one of Wales’ best number nines both for his on-field displays and the force of his personality off the field.