The Welsh full-back picked up the Pat Marshall Trophy at a dinner in London on Monday night to add to his collection of accolades since the tour.
Past winners of the award include Martin Johnson, Jonny Wilkinson, Sam Warburton, Jonah Lomu and Lawrence Dallaglio.
RUWC chairman Adam Hathaway said: "Leigh was a convincing winner of our vote and a worthy recipient of the award not only for his performances for the Lions but his displays in the Six Nations earlier in the year."
Shortlisted for the IRB Player of the Year award, Halfpenny was named Player of the Tournament after helping Wales to the RBS 6 Nations title in March.
BBC Wales' Sports Personality of the Year then came second to Wimbledon champion Andy Murray in the BBC's main Sports Personality of the Year vote.
The 25-year-old scored 49 points in the summer's three Lions Test matches, breaking Neil Jenkins' record for most points in a series including 21 in the 41-16 third Test win in Sydney.
Lions coach Warren Gatland won the Special Award for lifetime achievement joining amongst others Sir Clive Woodward, Cliff Morgan, Jim Telfer and Sir Ian McGeechan on the roll of honour.
Tankards for unsung heroes of rugby were presented to Rob Smith the former Wasps player, coach and academy manager, Sam Drury who has played 700 games for Ossett Rugby Club and Roy Lewis, a stalwart of Ebbw Vale.
- Sports & Recreation
- Sam Warburton
- Jonny Wilkinson
- Martin Johnson