Alex Kozinski (/kəˈzɪnski/; born July 23, 1950) is a Romanian-American jurist and lawyer who was a judge on the U.S. Court of Appeals for the Ninth Circuit from 1985 to 2017. He was a prominent and influential judge, and many of his law clerks went on to clerk for U.S. Supreme Court justices.

Kozinski's judicial career ended in 2017 when he retired after over a dozen of his former female law clerks and legal staffers accused him of sexual harassment and abusive practices. Kozinski had previously faced an ethics hearing over inappropriate sexual material.

Kozinski was born in July 1950 to a Romanian Jewish family in Bucharest, under the rule of the Romanian People's Republic. Both of his parents were Holocaust survivors. Kozinski's father, Moses, spent four years in Transnistrian concentration camps where tens of thousands of Jews perished. His mother, Sabine, lived through the war years in a Romanian ghetto.

In 1958, Kozinski's parents applied to the Romanian government for permission to emigrate from the country. They received permission four years later in 1962, when Kozinski was 12 years old. Kozinski, who had grown up as a committed communist in Bucharest, became what he described as "an instant capitalist" when he took his first trip outside of the Iron Curtain, to Vienna, where he partook of such luxuries as chewing gum and bananas. Kozinski later recounted:

I remember leaving Romania, December 24, 1961. And I still remember being on the train, making plans for myself, how I would to go the West where people were oppressed and I would share my knowledge of Communism and help bring enlightenment by helping to tear down capitalism. ... And the next thing I remember, I was in Vienna, and I got bubblegum and chocolate, which were freely available. It was as though a cloud or veil had lifted. It was such a different world, you had real consumer goods. People weren't running around with shackles. Everything that had been said about the West was untrue. Bananas were plentiful. In Romania, my father used to have to work a half-day to get three bananas. I remember going with my parents to an open-air market in Vienna and seeing all these bananas, cheap, ... and wondering whether they would be there tomorrow. I looked a week later and they were still there. There was no conscious rethinking or recalculating my point of view. I was now an instant and fervent capitalist.

Kozinski's family immigrated to the United States in 1962 and settled in the Los Feliz neighborhood of Los Angeles, where his father ran a small grocery store.

Kozinski studied economics at the University of California, Los Angeles, graduating in 1972 with a Bachelor of Arts, cum laude. He then attended the UCLA School of Law, where he was a managing editor of the UCLA Law Review. He graduated in 1975 with a Juris Doctor ranked first in his class.

After law school, Kozinski clerked for judge (later Supreme Court justice) Anthony Kennedy of the U.S. Court of Appeals for the Ninth Circuit from 1975 to 1976, then for chief justice Warren Burger of the U.S. Supreme Court from 1976 to 1977. He then entered private practice as an associate with the law firms Forry, Golbert, Singer & Gelles from 1977 to 1979 and Covington & Burling from 1979 to 1981. He was a Deputy Legal Counsel of the Office of the President-Elect in Washington, D.C. (1980–81) and an Assistant Counsel for the Office of Counsel to the President in Washington, D.C. (1981). He was a Special Counsel for the Merit Systems Protection Board in Washington, D.C. (1981–82).