He said: "My goal was to win the gold medal for Fiji and we got it. Now my goal is to perform well for my new team.
"I am excited about signing for Edinburgh Rugby, and am looking forward to playing for the club.
"I am also excited about arriving in the city and meeting my new team mates."
After switching codes from rugby league, Mata has represented current World Rugby Sevens Series champions Fiji at nine events on the circuit, scoring 55 points through 11 tries.
The powerful middle-row, who can also play back-row, stands at 1.97 metres tall and weighs 116kg.
Mata further bolsters Edinburgh Rugby's pack for the 2016/17 season, joining new forward signings Nick Beavon, Lewis Carmichael, Kevin Bryce and Viliami Fihaki at the capital club.
Edinburgh Rugby Head Coach Alan Solomons said: "We are delighted to welcome Bill to the club.
"He is a hugely talented player who was part of the Fiji 7s team that recently won gold at the Rio Olympics.
"He is big, powerful and explosive and I believe he will add huge value to the team."
Guinness PRO12 Edinburgh News
63x46.png){kind=logo}