Marc Urselli (born January 31, 1977, in Aarau, Switzerland) is an Italian-Swiss freelance New York City & London-based audio engineer, music producer, mixing engineer, live sound engineer, remixer, sound designer, composer, musician, contributor, and blogger.

He has been nominated for a Grammy Award seven times and he has won the award three times.

He is best known for his work as a recording and mixing engineer (live and in the studio) in the genres of rock, jazz, metal, pop, avantguarde/experimental and contemporary/new music with artists such as Lou Reed, Nick Cave, Mike Patton, U2, Elton John, Kesha, Joan Jett, Les Paul, Jack DeJohnette, John Patitucci, Esperanza Spalding, John Zorn, and Laurie Anderson.