The Dubliner starred in the pivotal out-half role as Ireland won only their third ever Grand Slam and made more history with a series win in Australia and their first ever victory over New Zealand on home soil. He was also central to Leinster's unprecedented Champions Cup and GUINNESS PRO14 double.
Recently named the World Rugby Player of the Year, Sexton is the first rugby player to win the RTÉ Sportsperson of the Year award since his former team-mate Brian O'Driscoll in 2009, the year of Ireland's second Grand Slam.
Attending the ceremony in Donnybrook with his wife Laura, Sexton paid tribute to her, his team-mates and coaches for their support in helping him to become the player he is as a standard bearer for both province and country.
"I'd like to thank all the team-mates and coaches. The Irish coaches are top class, world class. They make your job a little bit easier, and all your team-mates as well.
"I feel a bit bad accepting an individual award as a number 10. You're meant to be the guy that sits in the background and tries to help control the team. You shouldn't be getting individual awards because it's the other guys that make you look good."
The title-winning Ireland and Leinster squads were nominated for the RTÉ Sport Team of the Year award, but lost out in the public vote to the Ireland Women's hockey team, while hockey coach Graham Shaw was named the RTÉ Sport Manager of the Year, with Joe Schmidt and Leo Cullen among the nominees.