William Matthew Byrne Sr.
Senior Judge of the United States District Court for the Central District of California
In office September 18, 1966 – March 9, 1974
Senior Judge of the United States District Court for the Southern District of California
In office June 30, 1966 – September 18, 1966
Chief Judge of the United States District Court for the Southern District of California
In office 1965–1966
Preceded by	William Carey Mathes
Succeeded by	Thurmond Clarke
Judge of the United States District Court for the Southern District of California
In office September 27, 1950 – June 30, 1966
Appointed by	Harry S. Truman
Preceded by	James F. T. O'Connor
Succeeded by	A. Andrew Hauk
Member of the California State Assembly from the 66th district
In office January 5, 1925 - January 5, 1931
Preceded by	Otto J. Emme
Succeeded by	James E. Stockwell
Personal details
Born	William Matthew Byrne (1896-07-10)July 10, 1896 Bakersfield, California
Died	March 9, 1974(1974-03-09) (aged 77)
Political party	Republican
Children	William Matthew Byrne Jr.
Education	Loyola Law School (LL.B.)
Military service
Branch/service	United States Navy
Battles/wars	World War I

William Matthew Byrne Sr. (July 10, 1896 – March 9, 1974) was a United States district judge of the United States District Court for the Southern District of California.

Born in Bakersfield, California, Byrne received a Bachelor of Laws from Loyola Law School in Los Angeles, California in 1929. He was in the United States Navy from 1917 to 1919. He was in private practice in Los Angeles from 1929 to 1943. He was a member of the California State Assembly from 1925 to 1931, serving as Speaker pro tem from 1927 to 1931. He was a Judge of the Los Angeles Municipal Court from 1943 to 1948. He was a Judge of the Superior Court of California from 1948 to 1950.^[1]

Byrne received a recess appointment from President Harry S. Truman on September 27, 1950, to a seat on the United States District Court for the Southern District of California vacated by Judge James Francis Thaddeus O'Connor. He was nominated to the same position by President Truman on November 27, 1950. He was confirmed by the United States Senate on December 13, 1950, and received his commission on December 21, 1950. He served as Chief Judge from 1965 to 1966. He assumed senior status on June 30, 1966. Byrne was reassigned by operation of law to the United States District Court for the Central District of California on September 18, 1966, pursuant to 80 Stat. 75. His service terminated on March 9, 1974, due to his death.^[1]

• William Matthew Byrne Sr. at the Biographical Directory of Federal Judges, a publication of the Federal Judicial Center.

• Join California William M. Byrne