Davies, who will link up with Head Coach Richard Hill in early August, is an outstanding coach with a proven track record in club rugby.
The 46-year-old former Wales captain, born in Seven Sisters, spent a decade at Leeds Tykes between 1996 and 2006 taking the Yorkshire club from Division Three into top flight Premiership rugby. He steered Leeds to their Heineken Cup debut in 2003 and to a Powergen Cup win in 2005.
Highly regarded coach Davies also spent two years as Director of Rugby at the Scarlets, leading them to their first Heineken Cup semi-final in eight years.
A former policeman, who could play flanker, number eight or lock, made his playing debut for Llanelli in 1982 and played 331 games for the club, scoring 80 tries and 344 points. He captained the side for four consecutive seasons between 1988 and 1992 and again for the 1995/96 season, which was his final year at Stradey Park.
Davies also enjoyed acclaim on the international stage for Wales, gaining 46 caps and scoring five tries for his country. He made his debut as a 21-year-old against England in the 1985 Five Nations in Cardiff and was part of the Wales squad at the Rugby World Cup of 1987 and 1991.
Charlie Little, General Manager at Warriors, said: "I am delighted that we have agreed terms with WRU and Phil that will ensure he is with us at the beginning of August and ahead of the pre season games.
"Phil is another RFU Level 5 and, together and Richard Hill and Andrew Stanley, we now have a very qualified coaching department. I know Richard and Phil have spoken before about working together and he was top of the list so delighted to get 'our man'.
"Phil is a coach who has had great success at this level and knows what it takes to guide a team around the Championship and go on to be successful at the very top level.
"I know he is champing at the bit to get started and is keen to get stuck in with our forwards and work closely with Richard Hill to develop our style of play."