In 1978 Thun moved to Milan, where he met and started working with Ettore Sottsass. In 1981, he was a co-founder of the Memphis group, the design movement that so shaped events in the eighties. In the next year, the Vienna Academy for Applied Arts appointed him to the chair in product design and ceramics.
In 1984 he founded the Studio Matteo Thun in Milan. Between 1990 and 1995 he worked as Creative Director for Swatch and as design consultant for WMF. He developed the corporate identity for Dunkin' Donuts, Campari, Lavazza, Rosenthal and Vorwerk.
Matteo Thun won the ADI Compasso d'Oro Award for design excellence three times and was shortlisted again for the "Girly" product line for Catalano in 2004. The studio Matteo Thun designed numerous interior decorations as for example the Side Hotel in Hamburg, which was chosen as Hotel of the Year in 2001. The Vigilius mountain resort won the Wallpaper Design Award in 2004 and the Radisson SAS Frankfurt was chosen as the "best hotel opened in the year" in the Worldwide Hospitality Awards in 2005.
Matteo Thun designed the new look for the facade of the Palazzo del Cinema during 61st, 62nd and 63rd editions of the Venice Film Festival, in September 2004/05/06.
He was inducted into the New Yorker Interior Hall of Fame in December 2004. Also he is a member of RIBA, the Royal Institute of British Architects.