Favaro, the son of former Italy lock Roberto Favaro, started playing rugby aged nine while living in Zero Branco, on the advice of a family friend. He began his career playing for the Treviso under-19 team before stepping up to the Super 10 with Rovigo and Overmach Parma. Favaro was an early developer and, at the age of 20, was the youngest player included in Nick Mallett's squad for the 2009 Six Nations Championship. Favaro did not feature in the Championship; he subsequently made his debut against Australia in the 2009 Summer tour of the Southern Hemisphere. In June 2010 he joined Aironi for their first season in the Magners League. On 18 February 2015 it was announced that Favaro would sign for the Scottish side Glasgow Warriors for the 2015–16 season in the summer of 2015. Favaro has signed until May 2017.