Federal & State Judges
254 judges — Article III appointments from the Federal Judicial Center directory.
James Lowell OakesChief JudgeSecond Circuit Court of Appeals · 1970–2007- Natalia Cokinos Oakes2019–2022
- James E. Oakley1988–2010
- Dallin Harris Oaks1980–1984
- Barack Hussein Obama 2
- Marion L. Obera
Louis Falk OberdorferDistrict of Columbia District Court · 1977–2013- Daphne A. ObergCurrently serving
- David B. Oberholtzer2002–2020
- Richard J. Oberholzer1987–2008
- Sheila K. Oberto
- Charles H. O'Brien1987–1994
- Cornelius J. O'Brien1990–2003
- Dennis D O'Brien1985–2013
Donald Eugene O'BrienChief JudgeIowa Southern District Court · 1978–2015
Ernest Aloysius O'BrienMichigan Eastern District Court · 1931–1948- Gregory C., Jr. O'Brien1987–2005
- Henry X. O'Brien1962–1983
- Robert H. O'Brien1981–1999
Terrence L. O'BrienTenth Circuit Court of Appeals · 2002–2013- Timothy W. O'Brien1971–1985
- Ricardo Roces OcampoCurrently serving2008–present
- Frank J. Ochoa1997–2015
- Gilbert Glen OchoaCurrently serving2007–present
- Nathan Ochsner
Ambrose O'Connell1944–1962
Beverly Reid O'ConnellCalifornia Central District Court · 2005–2017- Edward Y. O'Connell1987–2000
- Jeremiah Edward O'Connell1948–1956
- John Joseph O'ConnellThird Circuit Court of Appeals · 1945–1949
- 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
James Francis Thaddeus O'ConnorCalifornia Southern District Court · 1940–1949- Kathleen Rose O'ConnorCurrently serving2002–present
- Kimberly A. O'Connor2006–2023
- Maureen O'ConnorCurrently serving2003–present
Reed Charles O'ConnorChief JudgeCurrently servingTexas Northern District Court · 2007–present
Sandra Day O'ConnorSupreme Court of the United States · 1979–2023
Robert J. O'Conor Jr.Texas Southern District Court · 1975–1984- John S. Oda
- 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
Daniel William O'DonoghueDistrict of Columbia District Court · 1932–1948- Peter J. O'Donoghue1996–2029
- J. Scott Odorisi
- William O'Dwyer
James Paul OetkenCurrently servingNew York Southern District Court · 2011–present- 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
- Isaac Stockton Keith OgierCalifornia Southern District Court · 1854–1861
- Norma Mcgee OgleCurrently serving1998–present
- John D. OglesbyCurrently serving2000–present
- James B. O'Grady
Liam O'GradyVirginia Eastern District Court · 2007–2023- Sandra Gardebring Ogren1989–1998
- Gail D. Ohanesian1998–2008
- James P. O'Hara
- Michael D. O'Hara1963–1968
- Patrick J. O'Hara
Christine Patricia O'HearnCurrently servingNew Jersey District Court · 2021–present- Daniel Joseph O'Hern1981–2000
- Kevin A OhlsonCurrently serving2011–present
Jinsook OhtaCurrently servingCalifornia Southern District Court · 2021–present- Sam OhtaCurrently serving2000–present
- Vincent Hichiro Okamoto2002–2020
William Clark O'KelleyChief JudgeGeorgia Northern District Court · 1970–2017- Dan Thomas Oki
- Neil P. OlackCurrently serving2006–present
- J. Dominique Olcomendy
- William D. Old 32013–2024
- Margaret Lynn OldendorfCurrently serving2005–present
- Charles H. Older1968–1987
Andrew Stephen OldhamCurrently servingFifth Circuit Court of Appeals · 2018–present- Walter Olds1889–1893
- Jerry C. Oldshue jrCurrently serving2015–present
- Kathleen Elizabeth O'Leary1986–2000
- Welsey J. Oler jrCurrently serving2012–present
Fernando Manzano OlguinCurrently servingCalifornia Central District Court · 2013–present
Abram Baldwin OlinDistrict of Columbia District Court · 1863–1879- A Dayton Oliphant1948–1957
- Ray Jesse Olivarri2019–2020
- Jerrold S. Oliver1974–1989