The California Golden Bears rugby team is the college rugby team of the University of California, Berkeley. The Golden Bears have won 33 championships since the national collegiate championships for rugby began in 1980. Current head coach and Cal alumnus Jack Clark took over the team in 1984, and has achieved prolonged success, leading the Bears to 29 national titles, including twelve consecutive championships from 1991 to 2002, five more consecutive titles from 2004 to 2008, and back-to-back titles in 2010 to 2011 and 2016 to 2017.

Cal also has competed in the Collegiate Rugby Championship (CRC), the highest profile college rugby sevens tournament in the U.S., winning the title each year from 2013 to 2017. The CRC was held every June from 2011 through 2019 at Subaru Park in the Philadelphia area. Cal also reached the finals of the 2010 CRC, losing to Utah in sudden death extra time, and finished third in the 2012 CRC.

Cal also competes for the "World Cup," which is awarded to the winner of the annual series between Cal and the University of British Columbia.

Cal Rugby's home is at 6,900-seat Witter Rugby Field, located near California Memorial Stadium in Strawberry Canyon.

Rugby began play at Cal in 1882 and continued until 1886, when it was replaced by American football. During the next decade, American football was becoming an increasingly violent sport - the ball carrier would often be pushed and pulled up the field by his own players in massive formations that often resulted in serious injuries. In 1905, 18 deaths and 159 injuries were reported in various football competitions. That year President Theodore Roosevelt lobbied Ivy League representatives to alter the game in order to eliminate or at least reduce its prevalent injuries. This resulted in numerous rule changes agreed upon by the majority of American schools.

Led by Cal and Stanford, universities of the West Coast took a different path, eliminating America football and changing their game to Rugby union. Other schools that made the switch included Nevada, St. Mary's, Santa Clara, and USC (in 1911). Because the switch to rugby occurred only on the West Coast, the number of teams to play against remained small. This led to schools scheduling games against local clubs and reaching out to rugby powers in Australia, New Zealand, as well as Canada.

Cal and Stanford's traditional rivalry game–the Big Game–became a rugby union match, with the winner invited by the British Columbia Rugby Union to a tournament in Vancouver over the Christmas holidays to play for the Cooper Keith Trophy. While Cal won the Cooper cup in 1910, in total it only won three Big Games during this 9 year period. Due to various causes, including students' frustration with the results, the Associated Students of the University of California voted to leave the agreement, and along with other west coast universities, return to American football. From 1906 to 1914, Cal's rugby record was 78 wings, 21 losses and 10 ties. Following the switch back to football, Cal continued to play rugby, but it was officially considered to be a "minor" sport.

Primarily Cal, Stanford, and Santa Clara players composed the two US Olympic rugby teams (1920 & 1924) and claimed fame by winning both Gold medals. Prior to the introduction of Rugby 7s at the 2016 Summer Olympics, 1924 was the last time the Olympic Games staged a rugby competition.