Tonetti has represented Ireland at U19 and U20 level and was part of the 2007 U20 6 Nations Grand Slam winning team alongside current Connacht players Andrew Browne, Paul O'Donohoe, TJ Anderson and Niall O'Connor.
A former pupil of St. Gerard's School in Bray, Kyle joined the Leinster Academy in 2007 and spent 2 years professionally contracted to the Province, earning 21 Leinster 'A' caps and 3 senior caps, the last against Connacht in April 2010 in the Sportsground.
Kyle's contract will see him play at the Sportsground until at least the end of the 2011/12 season.
Speaking about the signing Head Coach Eric Elwood said:
"I'm really looking forward to working with Kyle again, having known him since the '07 U20's team that won the 6 Nations and I'm sure he will fit nicely into the squad. We're looking forward to him joining up with the team and working with him again."