M
- Bernardino Machado, president (2001)
- Fernão de Magalhães, explorer (1945; 1993)
- Sebastião de Magalhães Lima, journalist and statesman (1978)
- Ferdinand Magellan, explorer (1945; 1993)
- José Malhoa, painter (2005)
- Manuel I, king (1995; 1996)
- Manuel II, king (1910)
- João Abel Manta (born 1928), cartoonist (2005)
- Guglielmo Marconi, Italian inventor (2000)
- Maria I, queen (1997)
- Maria II, queen (1853; 1935; 1953; 2003)
- Mark the Evangelist, apostle (1993)
- Bernardo Marques, painter (painting shown 1998)
- Martinho de Dume, archbishop and saint (1953)
- Osvaldo Martins (born 1972), fashion designer (2004)
- Jaime Martins Barata (1899-1970), painter (1999)
- Jacinta and Francisco Marto, siblings who saw visions of Mary (1992; 2000)
- Mary, saint, mother of Jesus (1946; 1950; 1956; 1967; 1974; 1977; 1979; 1981; 1983; 1993; 2000)
- Fernão Mendes Pinto, explorer (1980)
- Emílio Garrastazu Médici, Brazilian president (1973)
- Thomaz de Mello, graphic artist (2006)
- Gonçalo Mendes da Maia, knight, military commander (1927)
- Michael, archangel (1993)
- Carolina Michaëlis, philologist (2001; 2009)
- Aureliano de Mira Fernandes, mathematician (2008)
- Jean Monnet, French statesman (1988)
- Alexandra Moura (born 1973), fashion designer (2004)
- Wolfgang Amadeus Mozart, Austrian composer (1993; 2006)
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