Matias Tosi was born in Buenos Aires. He began by taking dancing lessons then followed up with drama and singing lessons in his hometown. He continued his studies with Hans Sotin, Wolfgang Brendel and Saverio Suárez-Ribaudo in Munich and made his debut in 1997 at the Teatro Nacional Cervantes in Argentina.

In 1999 Matias Tosi joined the opera studio of the Teatro Colón of Buenos Aires where he interpreted among others the role of Ferrando in Il Trovatore and Antonio in The Marriage of Figaro. He was engaged as visiting artist for the role of Crespel in The Tales of Hoffmann at the Chimsee-Festival, Don Alfonso in Cosi Fan Tutte and Kanzler in Die Prinzessin auf der Erbse by Ernest Toch at the Jungle Oper in Stuttgart. In 2004, he was among the cast of Scherz, Satire, Ironie und tiefere Bedeutung by Detlev Glanert at the Stadttheater of Regensburg. In November 2004, he was one of the finalists in a UNESCO international singing contest, for his role as Leporello in Mozart’s Don Giovanni. In Febrary 2005, he made his debut at the Stadttheater of Rastibonne in the role of Escamillo in Carmen. He has also played in Busoni’s Faust at the Staatsoper of Stuttgart.

Since 2007 Matias Tosi has been a member of the Staatsoper Company of Stuttgart where he has interpreted, among other roles, Escamillo in Carmen and Figaro in Mozart’s The Marriage of Figaro. In 2009 he played Zurga in The Pearl Fishers for the Opera Mauritius Festival.