O'Meara (Meara, O'Mara, Mara, Marah) is an Irish surname, anglicised from Ó Meadhra, originating in County Tipperary in Ireland.

• Andrew P. O'Meara (1907–2005), United States Army general
• Barry Edward O'Meara (1786–1836), Irish surgeon
• Basil O'Meara (1892–1971), Canadian sports journalist
• Brian O'Meara (rugby union) (born 1976), Irish rugby union footballer
• Brian O'Meara (Kilruane MacDonagh's hurler) (born 1990), Irish hurler
• Brian O'Meara (Mullinahone hurler) (born 1973), Irish hurler for the Tipperary senior team
• Colin O'Meara (born 1963), voice actor
• David O'Meara, Canadian poet
• Dermod O'Meara, Irish physician, poet and parent of Edmund O'Meara
• Edmund O'Meara (1614–1681), Irish physiologist and child of Dermod O'Meara
• Edward O'Meara (1921–1992), American prelate of the Roman Catholic Church
• Eileen O'Meara, American artist
• Eleanor O'Meara (died 2000), Canadian figure skater
• Frank O'Meara (1853–1888), Irish artist
• Frank O'Meara, Irish songwriter
• Ger O'Meara (born 1985), hurler and Gaelic footballer
• Jaeger O'Meara (born 1994), professional Australian rules footballer
• James O'Meara (1919–1974), Royal Air Force officer and fighter pilot
• Jane O'Meara Sanders (born 1950), American social worker, college administrator and political staffer
• Jo O'Meara (born 1979), English singer-songwriter, television personality and actress
• John Corbett O'Meara (born 1933), United States federal judge
• John O'Meara (politician) (1856–1904), Liberal Party Member of Parliament in New Zealand
• John J. O'Meara (1915–2003), Irish classical scholar and historian of ancient and medieval philosophy
• Kathleen O'Meara (politician) (born 1960), Irish politician
• Kathleen O'Meara (writer) (1839–1888), Irish-French Catholic writer
• Mark O'Meara (born 1957), American professional golfer
• Martin O'Meara (1885–1935), Irish-born Australian recipient of the Victoria Cross
• Mike O'Meara (born 1959), podcast personality
• O. Timothy O'Meara (1928–2018), American mathematician
• Patrick O'Meara (born 1947), Master of Van Mildert College and Professor at Durham University
• Patrick O. O'Meara (1938–2021), author and professor
• Peter O'Meara (born 1969), Irish actor
• Peter O'Meara (rugby union), CEO of the Western Force rugby union team
• Richard O'Meara, United States Brigadier General
• Ryan O'Meara (born 1984), American ice dancer
• Seán O'Meara (songwriter), Irish songwriter
• Seán O'Meara (Offaly hurler) (fl. 1980–1981), Irish hurler
• Seán O'Meara (Tipperary hurler) (1951–2010), Irish hurler
• Shane O'Meara (born 1992), Irish actor
• Walter O'Meara (1897–1989), American author

• Anne Meara (1929–2015), American actress and comedian

• James O'Mara (1873–1948), Irish businessman and politician
• Jared O'Mara (born 1981), British politician
• Jason O'Mara (born 1972), Irish-American actor
• Joseph O'Mara (1864–1927), Irish opera singer
• Kate O'Mara (1939–2014), English actress and writer

• Jack Mara (1908–1965), co-owner of the New York Giants
• John Mara (born 1954), president, CEO, and co-owner of the New York Giants
• Kate Mara (born 1983), American actress and fashion model
• Rooney Mara (born 1985), American actress and fashion designer
• Tim Mara (1887–1959), founder and administrator of the New York Giants and grandparent of Timothy J. Mara
• Timothy J. Mara (c. 1935 – 1995), American businessman, part owner of the New York Giants football team, and grandchild of Tim Mara
• Wellington Mara (1916–2005), co-owner of the New York Giants and child of Tim Mara

• Meara (disambiguation)