Owain Doull, Tao Geoghegan Hart and former world time trial champion Vasil Kiryienka make up the rest of the team.
The race starts in Edinburgh on September 3 and is stacked with stages designed for the sprinters. Despite announcing that he will leave Team Sky at end of the season, cutting his contract short by a year, Viviani has been in scintillating form in recent weeks. The Italian won the Cyclassics Hamburg before backing that up with two stage wins at the Tour du Poitou Charentes, and then claimed the Bretagne Classic - Ouest-France last weekend. The 28-year-old has won four stages of the Tour of Britain during his career.
Kwiatkowski has also enjoyed a successful season, book-ending a strong Tour de France with wins in Milan-San Remo and the San Sebastian Classic.
Thomas will be using the event as his first race since the Tour de France. The Welshman won the opening prologue and wore the yellow jersey for several days in July before crashing out with a broken collarbone. He has targeted a stage win rather than the overall classification at the Tour of Britain and has stated his desire to compete in the World Championships in September.
"The support from the British fans is always fantastic and it's going to be great to race at home. We've got a strong squad coming and I'm really looking forward to it," Thomas said in a statement released by the team.
"Coming back to Cardiff is going to be special and it's something the Welsh guys have been talking about since the route was announced. I'm sure the fans will do us proud."
The Tour of Britain concludes in Cardiff on September 10.
Team Sky for the Tour of Britain: Geraint Thomas, Elia Viviani, Owain Doull, Tao Geoghegan Hart, Vasil Kiryienka and Michal Kwiatkowski.