The versatile fly half, who can also operate at full back or centre, has enjoyed a stunning career in European rugby.
The 32-year-old represented Manly in Australia and graduated through the ranks to represent his country at Sevens levelbefore joining Connacht in 2004.
Warwick later starred for Munster during a glittering period between 2007 and 2011 as the club wonthe Heineken Cup in 2007/08 and were twice Celtic League winners in 2008/09 and 2010/11.
The Australian ace, who has also twice represented the Barbarians, has spent the last two years as part of a star-studded line-up at Stade Francais and will now make a move this summer to the Aviva Premiership and the Warriors.
Head Coach Richard Hill described Warwick as pivotal signing for the club, just days after confirmation that Argentina international back row Leonardo Senatore had also been recruited from next season.
"Paul is a winner, very serious about his rugby and very competitive," said Hill. "His attitude is absolutely spot-on for the culture we are developing at Sixways.
"I want players here with a winning mentality. That's not just a phrase you throw about; you have got to do something about it to achieve it. You have to study the game and your own performances to get better and truly push yourself.
"Paul wants to win rugby matches and that mentality and professionalism is massive.
"I want Paul to play outside half because he will bring other people into the game. Players will improve around him," added Hill.
"He can put people through holes, can beat defences and offload in the tackle. Everybody will be able to play off him and he is an unselfish player who will bring the best out of the Warriors.
"Paul is a versatile player and attack minded, he is someone who will look to really fire our back line."