The California Republican Assembly is a group of conservative California Republicans who act as what many would characterize as a right-wing lobby group.

The CRA can date its origin to the 1930s and was an early opponent of Governor Earl Warren, whom it regarded as far too liberal and far too cooperative with Democrats to merit support by conservatives. This faction was largely supportive of the efforts of Barry Goldwater's Presidential bid and helped him finalize his nomination at the 1964 Republican National Convention held in San Francisco. Later that year it helped the cause of George Murphy, a former movie actor and close friend of Ronald Reagan in being elected to the United States Senate, and then helped Reagan himself to be elected governor of California in 1966.

The group claims to hold much of the responsibility for the "Reagan Revolution ". Unlike some other conservative political groups, it makes no pretense at being nonpartisan; it is forbidden by its charter from supporting any candidates who are not Republicans. Its only goal is to influence the Republican Party to remain very conservative. It is pro-life and pro-"family values" but otherwise supports a limited-government agenda calling for lower taxes and less governmental regulation. In the 1990s it spawned a national organization based on its own efforts, the National Federation of Republican Assemblies, which now has affilates in approximately forty states.

Members of the group now dominate the statewide California Republican Party and many of its affiliated county organizations. Critics of the group, including those within Republican circles, note that since the group became truly dominant within the party that Republicans had won no statewide offices within California until Arnold Schwarzenegger won the 2003 California gubernatorial recall election and that he did so without CRA support, as it had supported third-place finisher Tom McClintock instead. They feel that its agenda is now too conservative ever to be accepted on a statewide basis within California and that unless its members relinquish their positions of party leadership that Republicans in California will constitute essentially a permanent minority. CRA members counter that without its influence, the California Republican Party would resemble the California Democratic Party so closely that voters, especially conservative ones, would essentially be left with little or no real choice.