BT Sport Academy prospect Luke Crosbie has also signed a full-time two-and-a-half-year professional deal with immediate effect, the club has confirmed.
Mata, a gold medal winner in rugby sevens at the 2016 Summer Olympics in Rio, has been in fine form for the Capital side since his return to action, and picked up the Try of the Month award for November for his effort against Southern Kings.
The 26-year-old back-row, who has four caps for Fiji, said he was ‘really pleased’ to be re-signing, adding: “My family and I have settled in the city and I’m really enjoying my rugby.
“Richard Cockerill has developed a great environment, both on and off the field, and it’s an exciting time to be part of the club.”
Formerly with Livingston RFC, Crosbie joined Currie as a teenager and broke through into the club’s first XV.
His performances for the BT Premiership side earned him a place in the Scotland Under-20 squad for the World Rugby Under-20 Championship in Georgia, where he helped the Scots to a best-ever placing of fifth.
Following the tournament, he was invited to Edinburgh’s summer training camp in St Andrews, and made his debut at back-row in the 16-15 PRO14 victory over Zebre at Myreside in October.
To date he has made eight appearances, scoring one try.
Crosbie said: “I always wanted to play for Edinburgh as a kid and I am proud and delighted to sign my first professional contract with them.
“I’m looking forward to working hard for the team and play my part in building Edinburgh’s already strong culture.”
Edinburgh head coach Richard Cockerill added: “We’re delighted that both Luke and Bill have committed their long-term futures to the club.
“Luke has progressed really well since making his debut earlier in the season, whilst Bill has been world class since his return to first XV action.
“Both players have bought into what we’re building here in Edinburgh and it’s a huge boost to the club to know that they have chosen to stay for at least the next two years.”