The 28-year-old, who began his career with four years at Lampre, has one win under his belt so far in 2019, at the Giro dell'Appennino. In May, he narrowly missed out on a Giro d'Italia stage victory, finishing second behind Dario Cataldo (Astana) in Como.
"I am very, very happy to join the Wolfpack," said Cattaneo via a team press release. "For me it is a dream because I have raced with Androni Giocattoli for three years, but my objective was to come back to the WorldTour and with Deceuninck-QuickStep I am going to the best team in the world, in my opinion.
"I am looking forward to helping the squad continue to be successful, as well as hopefully getting my own opportunities. Being an Italian, the Giro is always going to be the race closest to my heart, but in the past,I have raced the Tour of Flanders and I fell in love with the event; also Il Lombardia is very special to me, as it starts in my hometown and covers roads that I know very well."
Cattaneo, who won the Girobio in 2011 before turning pro, brings extra mountain and hill-climbing talent to a squad that already boasts Julian Alaphilippe, Bob Jungels and Remco Evenepoel, as well as James Knox and 2020 neo-pros Andrea Bagioli and João Almeida. Team boss Patrick Lefevere hailed Cattaneo's consistency as he welcomed the Italian to the team.
"Mattia has shown himself to be a very solid and consistent rider," he said. "Off the back of a strong year that he has had so far, we recognised him as somebody that can give us continuity across a lot of races, work hard as a member of the Wolfpack, and hopefully create and seize his own opportunities."