The three-year deal kicks off as the tournament starts at the beginning of next month.
England flanker and Rugby World Cup winner Lewis Moody, Welsh full-back Lee Byrne and Scottish winger Sean Lamont will front this year's activity, giving fans the inside track on their team via video diaries, and feature on PoS.
"The new partnership provides us with a strong platform to engage with a much wider audience not just the hardcore fanbase," said Lee Bailey, Guinness sponsorship manager.
"It gives us our largest-ever presence in rugby with over 120 million in TV audiences watching."
The Guinness title sponsorship of Premiership Rugby ended in September but it remains the official beer of the competition.