The 48-year-old saw off South Africa’s Jacques Nienaber, New Zealand’s Ian Foster and Fiji’s Simon Raiwalui to win the award.
Farrell guided Ireland to Grand Slam glory in the Six Nations earlier this year as they began their World Cup campaign as the number-one ranked team in the worldPool stage victories over Romania, Tonga, South Africa and Scotland had Ireland on a 17-match winning streak before taking on New Zealand in the quarter-final.
Leinster quartet Dan Sheehan, Tadhg Furlong, Caelan Doris and Garry Ringrose also made the dream 15, in which Eben Etzebeth was surprisingly the only South African from their World Cup-winning team. Savea's fellow All Black Mark Tele’a won the Breakthrough Player of the Year after impressive performances on the wing.