People — M
Mark O'Regan
b. 1953
lawyer
Mark O'Reilly
b. 1976
Mark O'Riordan
b. 1980
Gaelic football player
Mark O. Robbins
physicist
Mark O'Rourke
b. 1962
curler
Mark O'Rowe
b. 1970
screenwriter
Mark O'Shea
b. 1977
singer
Mark O'Shea
b. 1956
zoologist
Mark O'Sullivan
b. 1973
Gaelic football player
Mark O'Sullivan
b. 1983
association football player
Mark O'Toole
b. 1964
musician
Mark O'Toole
b. 1963
Catholic priest
Mark Oakley
b. 1968
Anglican priest
Mark Oaten
b. 1964
politician
Mark Obenshain
b. 1962
lawyer
Mark Oberman
b. 1967
water polo player
Mark Occhilupo
b. 1966
surfer
Mark Ochieng
b. 1996
association football player
Mark Odejobi
b. 1988
rugby union player
Mark Odhiambo
b. 1993
athletics competitor
Mark of Aviano
1631 – 1699
presbyter
Mark of Cornwall
480 – 555
writer
Mark of Ephesus
1392 – 1445
philosopher
Mark of Lisbon
1511 – 1591
Catholic priest
Mark of the Caves
b. 1050
monk
Mark of Toledo
1101 – 1226
translator
Mark Offerdahl
b. 1987
rugby league player
Mark Ogilvie-Grant
1905 – 1969
diplomat
Mark 'Oh
b. 1970
club DJ
Mark Ohman
oceanographer
Mark Okerstrom
b. 1975
business executive
Mark Okey
politician
Mark Okoth Obama Ndesandjo
b. 1965
businessperson
Mark Okraku Mantey
b. 1974
journalist
Mark Olberding
b. 1956
basketball player
Mark Oldershaw
b. 1983
canoeist
Mark Oldman
b. 1969
writer
Mark Oldroyd
1843 – 1927
politician
Mark Olf
1905 – 1987
singer
Mark Oliphant
1901 – 2000
physicist
Mark Olive
b. 1962
chef
Mark Oliver Everett
b. 1963
singer
Mark Oliver Roosnupp
b. 1997
association football player
Mark Olshaker
b. 1951
writer
Mark Olson
b. 1957
curler
Mark Olson
b. 1961
singer-songwriter
Mark Olssen
b. 2000
political scientist
Mark Olver
b. 1988
ice hockey player
Mark Olver
comedian
Mark Ooijevaar
b. 1983
speed skater
Márk Opavszky
b. 2001
canoeist
Mark Opitz
b. 1952
record producer
Mark Oppenheimer
b. 1974
columnist
Mark Opstad
b. 1978
choir director
Mark Opzoomer
businessperson
Mark Orchard
b. 1978
cricketer
Mark Orchard
b. 1976
Australian rules football player
Mark Ordesky
b. 1963
film producer
Mark Ormerod
b. 1976
association football player
Mark Ormerod
b. 1957
Civil Service (United Kingdom)
Mark Ormrod
b. 1983
soldier
Mark Ormrod
b. 1982
athletics competitor
Mark Ormrod
1957 – 2020
medieval historian
Márk Orosz
b. 1989
association football player
Mark Orton
b. 1982
composer
Mark Orval
b. 1968
Australian rules football player
Mark Osborn
b. 1981
association football player
Mark Osborne
b. 1961
cricketer
Mark Osborne
b. 1970
film director
Mark Osborne
b. 1961
ice hockey player
Mark Oshiro
b. 1983
writer
Mark Osiecki
b. 1968
ice hockey player
Mark Osler
b. 1963
legal scholar
Mark Ostendarp
b. 1973
athletics competitor
Mark Otten
b. 1985
association football player
Mark Otway
1931 – 2014
tennis player
Mark Ouimet
b. 1949
politician
Mark Ouimet
b. 1971
ice hockey player
Mark Ouma
1960 – 2016
sports journalist
Mark Outterside
b. 1967
association football player
Mark Ovendale
1973 – 2011
association football player
Mark Ovenden
b. 1963
journalist
Mark Ovenden
composer
Mark Overmars
b. 1958
mathematician
Mark Overton
b. 1950
scientist
Mark Owen
b. 1972
singer-songwriter
Mark Owen Lee
1930 – 2019
music journalist
Mark Owen-Taylor
b. 2000
actor
Mark Owen
b. 1976
writer
Mark Owens
politician
Mark Owuya
b. 1989
ice hockey player
Mark Oxley
b. 1990
association football player
Mark Ozer
b. 1964
tennis player
Mark P. Atkinson
b. 1970
cricketer
Mark P. Brown
b. 1950
engineer
Mark P. Finlay
b. 1953
architect
Mark P. Fitzgerald
b. 1951
military officer
Mark P. Lagon
b. 1965
political scientist
Mark P. Leone
1940 – 2024
anthropologist
Mark P. Mahon
1930 – 2017
military personnel