Sidney Runyan Thomas (born August 14, 1953) is an American lawyer and jurist serving as a senior U.S. circuit judge of the United States Court of Appeals for the Ninth Circuit since 1996. He served as the Ninth Circuit's chief judge from 2014 to 2021. His chambers are located in Billings, Montana.
Sidney Runyan Thomas
Ninth Circuit Court of Appeals
Chief Judge — U.S. Court of Appeals for the Ninth Circuit
Born 1953 in Bozeman, MT
FJC ID: 2367
Career output and lasting influence
Opinions attributed per year · peak 11/year
Later decisions citing those opinions, per year · peak 168/year
Ninth Circuit Court of Appeals · 1996–
Both charts share the same year axis. Opinion counts include only opinions in our corpus attributed to this judge so far — a year at zero can mean an attribution gap, not judicial silence. Influence typically outlasts the career: citations keep climbing after the last opinion.
- Gender
- Male
- Race
- White
Prior employment
- Judicial Conference of the United StatesMember · 2014–2021
- Private practice, Billings, Montana1978–1995
- Rocky Mountain College, Billings, MontanaAdjunct instructor of law · 1982–1995
Appointments
U.S. Court of Appeals for the Ninth CircuitChief Judge1996–2023 · Appointed by William J. Clinton (Democratic)
Education
- University of Montana School of LawJ.D. · 1978
- Montana State UniversityB.A. · 1975