Barrett had a tough task in filling the boots of Dan Carter, last year's player of the year who led the All Blacks to their second successive World Cup, but did the job admirably as New Zealand maintained their dominance of the sport.
His award completed a hat-trick of titles for New Zealand as Steve Hansen won coach of the year and the All Blacks were named team of the year after notching 18 wins in a row, a streak that ended last week when they lost to Ireland for the first time.
"I'm hugely proud and humbled to receive this award," said Barrett. "It's a team game and I accept it on behalf of the team."
Hansen paid tribute to the squad players "who keep the first team honest".
"We lost a few big trees after 2011 but that makes space for new guys to flourish," he said.
England lock Mario Itoji, who was also nominated for the player of the year award, took the young player honours.
Former South Africa captain Jean de Villiers won the International Rugby Players Association's special merit award for continued service to rugby.
Irish rugby stalwart Syd Millar, formerly head of the sport's governing body, picked up the Vernon Pugh Award for distinguished service.
Millar won 37 caps for Ireland, went on three British and Irish Lions tours, coached Ireland and the Lions, and was a key figure in the establishment of the Rugby World Cup.
(Editing by Peter Rutherford)
