Tuohy joined Connacht in 2009 from English Division One side Cornish Pirates. Known for his excellent finishing and blistering pace, as well as finishing third in the National League's try-scoring stakes, he first came to the attention of the Ireland Sevens management.
After an impressive run of performances, he earned himself a place in Michael Bradley's Ireland 'A' team that beat the USA in the Churchill Cup.
He went on to compete in the Sevens World Cup in Dubai in 2009, helping Ireland gain a famous victory over Australia, before joining Connacht.
Tuohy has scored 10 tries for the province in 20 Magners League games and five Amlin Challenge Cup fixtures, and touched down in Connacht's historic win over Samoa earlier in the season.
Speaking about extending his stay at the Sportsground, the Limerick native said: "I'm delighted to continue my time here at Connacht, there's a real buzz about the squad at the moment and we're playing some great rugby.
"It's a pleasure to part of this team and hopefully we can finish the league out with some great performances."
Connacht have announced the signing of 22-year-old scrum half David Moore from Harlequins.
Moore, who joined Harlequins from the Leinster Academy at the beginning of this season, was a member of Eric Elwood's Ireland Under-20 team in 2008.
The former Blackrock College pupil represented Ireland Schools and went on to win an Under-19 cap before making the step up to the Under-20 grade where he won a total of eight caps.
This season, the 6ft, 91kg back has played nine times for Harlequins, including one appearance against I Cavalieri Estra in Connacht's Amlin Challenge Cup pool.
Moore explained: "I'm thrilled to be returning back home to Ireland and I'm really looking forward to working under Eric Elwood at Connacht. They are playing a very positive brand of rugby and I look forward to being part of the set-up."
Meanwhile, Galway native Eoin McKeon has also to put pen to paper on a new deal with the province.
The 6ft 2in, 101 kg former Coláiste Iognáid student made his debut last season away to the Scarlets and has made three senior appearances for Connacht in the current campaign, including that famous win over Samoa last November.
McKeon, who is just 19, has represented Ireland at Youths and Under-19 level and played in the Ireland Under-20s' Six Nations win over Italy in February before injury ruled him out for the rest of the tournament.
A strong, ball-carrying number 8, he is the latest graduate of the Connacht Academy and makes the step up to a development contract for the coming season.
Commenting on his new deal, McKeon said: "I am delighted to be making the next step in my career here at Connacht. I am extremely grateful to Academy manager Nigel Carolan for helping me to make the step and I look forward to being part of the senior squad next season."