{ "id": "eph86sp1f2", "slug": "diarmuid-f-oscannlain", "title": "Diarmuid F. O'Scannlain", "updated": "2026-10-15", "topic_path": [ { "id": "society", "label": "Society and history", "api_url": "https://www.edgepedia.org/api/v1/topics/society" }, { "id": "society.law", "label": "Law and justice", "api_url": "https://www.edgepedia.org/api/v1/topics/society.law" }, { "id": "society.law.practice", "label": "Courts and legal practice", "api_url": "https://www.edgepedia.org/api/v1/topics/society.law.practice" }, { "id": "society.law.practice.people", "label": "Legal biographies", "api_url": "https://www.edgepedia.org/api/v1/topics/society.law.practice.people" }, { "id": "society.law.practice.people.people.judges.us", "label": "United States judges", "api_url": "https://www.edgepedia.org/api/v1/topics/society.law.practice.people.people.judges.us" }, { "id": "society.law.practice.people.people.judges.us.federal", "label": "US federal judges", "api_url": "https://www.edgepedia.org/api/v1/topics/society.law.practice.people.people.judges.us.federal" }, { "id": "society.law.practice.people.people.judges.us.federal.article3", "label": "Article III judges (district and appellate)", "api_url": "https://www.edgepedia.org/api/v1/topics/society.law.practice.people.people.judges.us.federal.article3" }, { "id": "society.law.practice.people.people.judges.us.federal.article3.appeals-judges", "label": "United States courts of appeals judges", "api_url": "https://www.edgepedia.org/api/v1/topics/society.law.practice.people.people.judges.us.federal.article3.appeals-judges" }, { "id": "society.law.practice.people.people.judges.us.federal.article3.appeals-judges.alpha-o-to-s", "label": "Surnames O to S", "api_url": "https://www.edgepedia.org/api/v1/topics/society.law.practice.people.people.judges.us.federal.article3.appeals-judges.alpha-o-to-s" } ], "geo": [ { "id": "geo.us.t2021.society.law.practice.people.people.judges.us.federal.article3.appeals-judges.alpha-o-to-s", "label": "United States · 2021 and later: Surnames O to S", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society.law.practice.people.people.judges.us.federal.article3.appeals-judges.alpha-o-to-s", "path": [ { "id": "geo.us", "label": "United States", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us" }, { "id": "geo.us.t2021", "label": "United States · 2021 and later", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021" }, { "id": "geo.us.t2021.society", "label": "Society and history", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society" }, { "id": "geo.us.t2021.society.law", "label": "Law and justice", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society.law" }, { "id": "geo.us.t2021.society.law.practice", "label": "Courts and legal practice", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society.law.practice" }, { "id": "geo.us.t2021.society.law.practice.people", "label": "Legal biographies", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society.law.practice.people" }, { "id": "geo.us.t2021.society.law.practice.people.people.judges.us", "label": "United States judges", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society.law.practice.people.people.judges.us" }, { "id": "geo.us.t2021.society.law.practice.people.people.judges.us.federal", "label": "US federal judges", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society.law.practice.people.people.judges.us.federal" }, { "id": "geo.us.t2021.society.law.practice.people.people.judges.us.federal.article3.appeals-judges", "label": "United States courts of appeals judges", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society.law.practice.people.people.judges.us.federal.article3.appeals-judges" }, { "id": "geo.us.t2021.society.law.practice.people.people.judges.us.federal.article3.appeals-judges.alpha-o-to-s", "label": "Surnames O to S", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t2021.society.law.practice.people.people.judges.us.federal.article3.appeals-judges.alpha-o-to-s" } ] } ], "excerpt": "Diarmuid F. O'Scannlain, born 1937 in New York, is an American judge on the Ninth Circuit Court of Appeals, appointed by Reagan in 1986 and on senior status since 2016.", "snippet": "Diarmuid F. O'Scannlain, born 1937 in New York, is an American judge on the Ninth Circuit Court of Appeals, appointed by Reagan in 1986 and on senior status since 2016.", "node": "society.law.practice.people.people.judges.us.federal.article3.appeals-judges.alpha-o-to-s", "markdown": "# Diarmuid F. O'Scannlain\n\nDiarmuid Fionntain O'Scannlain (born 1937) is an American jurist serving as a judge of the [United States Court of Appeals for the Ninth Circuit](https://www.edgepedia.org/united-states-court-of-appeals-for-the-ninth-circuit) since 1986.[1](https://www.fjc.gov/node/1385926) He was appointed by President Ronald Reagan, confirmed in 1986, and assumed senior status on December 31, 2016.[1](https://www.fjc.gov/node/1385926)\n\n| Fact | Detail |\n|---|---|\n| Court | U.S. Court of Appeals for the Ninth Circuit[1](https://www.fjc.gov/node/1385926) |\n| Appointed by | Ronald Reagan[1](https://www.fjc.gov/node/1385926) |\n| Confirmed | September 25, 1986, by voice vote[1](https://www.fjc.gov/node/1385926) |\n| Senior status | December 31, 2016[1](https://www.fjc.gov/node/1385926) |\n| Born | 1937 in New York, NY[1](https://www.fjc.gov/node/1385926) |\n| Education | B.A., St. John's University, 1957; J.D., Harvard Law School, 1963; LL.M., University of Virginia School of Law, 1992[1](https://www.fjc.gov/node/1385926) |\n\n## Early life and education\n\nO'Scannlain was born in 1937 in New York, New York.[1](https://www.fjc.gov/node/1385926) He received a [Bachelor of Arts](https://www.edgepedia.org/bachelor-of-arts) from St. John's University in 1957 and a [Juris Doctor](https://www.edgepedia.org/juris-doctor) from [Harvard Law School](https://www.edgepedia.org/harvard-law-school) in 1963.[1](https://www.fjc.gov/node/1385926) Later in his career, while serving on the federal bench, he earned a Master of Laws from the University of Virginia School of Law in 1992.[1](https://www.fjc.gov/node/1385926)\n\n## Legal career\n\nO'Scannlain served in the U.S. Army Reserve, JAG Corps, from 1955 to 1978, retiring with the rank of major.[1](https://www.fjc.gov/node/1385926) After law school, he worked as a tax attorney for Standard Oil Company of New Jersey in New York City from 1963 to 1965.[1](https://www.fjc.gov/node/1385926) He then entered private practice in [Portland, Oregon](https://www.edgepedia.org/portland-oregon), practicing there from 1965 to 1969 and again from 1975 to 1986.[1](https://www.fjc.gov/node/1385926)\n\nBetween his periods in private practice, O'Scannlain held several Oregon state government positions: he served as deputy attorney general of Oregon from 1969 to 1971, as the state's public utility commissioner from 1971 to 1973, and as director of the Oregon Department of Environmental Quality from 1973 to 1974.[1](https://www.fjc.gov/node/1385926)\n\nIn the early 1980s, O'Scannlain took part in federal advisory and review work. He served as a consultant to the Office of the President-Elect of the United States from 1980 to 1981, as a team leader on the President's Private Sector Survey on [Cost Control](https://www.edgepedia.org/cost-control) (the Grace Commission) from 1982 to 1983, and as chairman of the Advisory Panel to the Secretary of the U.S. Department of Energy from 1983 to 1985.[1](https://www.fjc.gov/node/1385926)\n\n## Federal judicial service\n\nPresident [Ronald Reagan](https://www.edgepedia.org/ronald-reagan) nominated O'Scannlain to the United States Court of Appeals for the Ninth Circuit on August 11, 1986.[1](https://www.fjc.gov/node/1385926) The Senate confirmed him by voice vote on September 25, 1986, and he received his commission on September 26, 1986.[1](https://www.fjc.gov/node/1385926) He served as an active judge for three decades and assumed senior status on December 31, 2016.[1](https://www.fjc.gov/node/1385926)\n\nIn 2017, O'Scannlain sat for an oral history interview conducted by Michael T. Reynolds as part of the Oral History of Distinguished American Judges project of the Institute of Judicial Administration at New York University School of Law; the video and transcript were published in 2020 and are available online.[1](https://www.fjc.gov/node/1385926)\n\n## References\n\n1. [O'Scannlain, Diarmuid Fionntain - Federal Judicial Center](https://www.fjc.gov/node/1385926)\n\n---\n*Topic: Encyclopedia › Society and history › Law and justice › Courts and legal practice › Legal biographies › United States judges › US federal judges › Article III judges (district and appellate) › United States courts of appeals judges › Surnames O to S*\n\n*Initially written Sep 27, 2026 · Reviewed: Sep 29, 2026 · Edited: Oct 15, 2026 · Last review: Sep 29, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/diarmuid-f-oscannlain", "markdown_url": "https://www.edgepedia.org/diarmuid-f-oscannlain.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"Diarmuid F. O'Scannlain\", Edgepedia (EdgeChat), https://www.edgepedia.org/diarmuid-f-oscannlain. Edgepedia Community License 1.0.", "credit_md": "\"[Diarmuid F. O'Scannlain](https://www.edgepedia.org/diarmuid-f-oscannlain)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/diarmuid-f-oscannlain](https://www.edgepedia.org/diarmuid-f-oscannlain). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"Diarmuid F. O'Scannlain\", Edgepedia (EdgeChat), https://www.edgepedia.org/diarmuid-f-oscannlain. Edgepedia Community License 1.0.", "speakable": "Diarmuid F. O'Scannlain, born 1937 in New York, is an American judge on the Ninth Circuit Court of Appeals, appointed by Reagan in 1986 and on senior status since 2016." }