Masi is a surname. Notable people with the surname include:
Alberto Masi (born 1992), Italian footballer
Alex Masi, Italian musician
Andrea Masi, Italian rugby player
Aristides Masi (born 1977), former Paraguayan footballer
Denis Masi (born 1942), British artist
Esala Masi (born 1974), retired Fijian footballer
Fabio De Masi (born 1980), German politician
Federico Masi (born 1990), Italian footballer
Francesco De Masi, Italian musician
Gianluca Masi, Italian astrophysicist
Giuseppe Di Masi (born 1981), Italian footballer
Jason Masi, American folk/rock singer-songwriter and musician
Julie Masi, Canadian musician
Kitso Masi (born 1984), Motswana actor
Lance de Masi (born 1949), president of the American University in Dubai
Manoa Masi (born 1974), former Fijian professional footballer
Mattia Masi (born 1984), Sammarinese footballer
Phil Masi, American baseball player
Reni Masi (born 1933 or 1934), former Canadian politician
Sébastien Masi, French Michelin-starred head chef in Ireland
