State Judges
164 judges — Article III appointments from the Federal Judicial Center directory.
- Natalia Cokinos Oakes2019–2022
- James E. Oakley1988–2010
- Dallin Harris Oaks1980–1984
- David B. Oberholtzer2002–2020
- Richard J. Oberholzer1987–2008
- Charles H. O'Brien1987–1994
- Cornelius J. O'Brien1990–2003
- Gregory C., Jr. O'Brien1987–2005
- Henry X. O'Brien1962–1983
- Robert H. O'Brien1981–1999
- Timothy W. O'Brien1971–1985
- Ricardo Roces OcampoCurrently serving2008–present
- Frank J. Ochoa1997–2015
- Gilbert Glen OchoaCurrently serving2007–present
Beverly Reid O'ConnellCalifornia Central District Court · 2005–2017- Edward Y. O'Connell1987–2000
- Jeremiah Edward O'Connell1948–1956
- Kenneth J. O'Connell1958–1977
- Kevin Michael O'Connell2015–2022
- Peter D. O'ConnellCurrently serving1994–present
- Stephen Cornelious O'Connell1955–1967
Earl Eugene O'ConnorChief JudgeKansas District Court · 1965–1998- Francis Patrick O'Connor1981–1997
- Frank D. O'Connor1976–1986
- Kathleen Rose O'ConnorCurrently serving2002–present
- Kimberly A. O'Connor2006–2023
- Maureen O'ConnorCurrently serving2003–present
Sandra Day O'ConnorSupreme Court of the United States · 1979–2023- Kurt S. OdenwaldCurrently serving2007–present
- Archie Odom1960–1967
- Frederick M. Odom1931–1944
- Wendell Albert Odom1971–1984
- James P. O'Donnell1983–1986
- Joanne B. O'Donnell2000–2016
- Terrance O'DonnellCurrently serving2003–present
- Terrence O'Donnell1995–2003
- William J. O'DonnellCourt of Appeals of Maryland · 1974–1976
- Peter J. O'Donoghue1996–2029
- Robert A. O'Farrell1981–2009
- T Scott OffuttCourt of Appeals of Maryland · 1920–1942
- Joseph O'Flaherty1998–2013
- Michael John O'GaraCurrently serving2009–present
- Thomas S. Ogata1974–1981
- E. Jeannette Ogden1996–2005
- Steven D. Ogden1999–2014
- Jack L. Ogg1973–1985
- Norma Mcgee OgleCurrently serving1998–present
- John D. OglesbyCurrently serving2000–present
- Sandra Gardebring Ogren1989–1998
- Gail D. Ohanesian1998–2008
- Michael D. O'Hara1963–1968
- Daniel Joseph O'Hern1981–2000
- Sam OhtaCurrently serving2000–present
- Vincent Hichiro Okamoto2002–2020
- William D. Old 32013–2024
- Margaret Lynn OldendorfCurrently serving2005–present
- Charles H. Older1968–1987
- Walter Olds1889–1893
- Kathleen Elizabeth O'Leary1986–2000
- Welsey J. Oler jrCurrently serving2012–present
- A Dayton Oliphant1948–1957
- Ray Jesse Olivarri2019–2020
- Jerrold S. Oliver1974–1989
- Ralph A. Oliver1938–1962
- Robert H. Oliver1998–2015
- Elizabeth Ufkes Olivera2010–2019
- Charlaine F. OlmedoCurrently serving2002–present
- Mario G. Olmos1983–1990
- Garrett W. Olney1998–2007
- Warren OlneyCalifornia Supreme Court · 1919–1921
- Emily OlshanskyCurrently serving2004–present
- Gregory Jerome OlsonCurrently serving2018–present
- Judith Ference OlsonCurrently serving2010–present
- Julius J. Olson1934–1948
- Lester E. Olson1966–1985
- Lynn Diane OlsonCurrently serving2007–present
- Ralph O. Olson1951–1955
- Robert M. Olson1972–1995
- Graciela Olvera2013–2014
- Martin J. O'Malley1943–1949
- Mary Ann O'Malley2009–2010
- William A. O'Malley1985–2006
- LaFel Earl Oman1971–1977
- Robert S. Ondrovic2021–2034
- Cecil Talmadge O'Neal1949–1955
- John Belton O'Neall1859–1863
- Stephen E. O'Neil1989–2001
- C William O'Neill1960–1978
- Harriet O'Neill1999–2010
Lawrence Joseph O'NeillChief JudgeCalifornia Eastern District Court · 1990–present- Robert F. O'NeillCurrently serving1999–present
- Vincent J., Jr. O'Neill2011–2012
- William Michael O'NeillCurrently serving2013–present
- Kelly O'Neill Levy2013–2916
- Tomson Tio OngCurrently serving2000–present
- Rafael Astraquill OngkekoCurrently serving2002–present
- Charles Austin O'NIELL1914–1949
- John Frank Onion jr1967–1988
- Marian P. Opala1978–2010
- Reuben OppenheimerCourt of Appeals of Maryland · 1964–1967