John Feehan, Chief Executive of Celtic Rugby, said: "The RaboDirect PRO12 features the top teams from Ireland, Wales, Scotland and Italy. Our competition is thriving with increased numbers going through turnstiles as well as increased TV audiences.
"The quality of our competition is such that 24 out of the 37 players selected for the 2013 Lions tour to Australia play in the RaboDirect PRO 12.
"We believe that this agreement with Sky will allow us to bring our tournament to an even bigger television audience.
"This is a milestone for Celtic Rugby as it is our first ever network coverage deal in the UK and Ireland."
Celtic Rugby are still in negotiations with other broadcasters and will be announcing further agreements in due course.