Viviani signed for on 24 October 2014 after considering offers from and the . He chose Team Sky because they were willing to help tailor his road programme to help with his track ambitions at the 2016 Summer Olympics in Rio de Janeiro. After winning Stage 2 of the Dubai Tour, Viviani headed to the Track World Championships in Yvelines winning two medals including bronze in his focused Olympic event, the omnium. Back on the road Viviani made a big leap forward, consistently winning at World Tour level winning stages at the Tour de Romandie, the Eneco Tour and winning his first Grand Tour stage at the Giro d'Italia on stage 2 into Genoa. He ended the season well, becoming the European Track Champion in the omnium, gaining Olympic qualification points in the process. He also won three stages at the Tour of Britain and finished where he started the season, winning in the Middle East, this time at the Abu Dhabi Tour.