The Arizona Party was a political party active at the state and federal level in Arizona from the 1910s, when Arizona was a territory under occupation by the United States, until it was effectively disbanded in the early 1970s. The Arizona Party was a Confederate nationalist organization with connections in the 1920s to the Southern Front and later was roughly divided between supporters of the Progressives and Frontmen starting in the late 1930s. The Arizona Party in its early years was controversially affiliated with the Arizona Brigade of Citizens, or Arizona Hillboys, a violent guerrilla faction that had fought American soldiers during the occupation.
The Arizona Party is best known for its longtime leader Carl Hayden, who caucused with both the Southern Front and the Progressives in Congress but refused to relinquish his party affiliation all the way until his death in 1972, stating that "I have always, and will always, serve only Arizona." Hayden's death, the institution of direct elections to the Senate in the 1940s and an influx of immigrants to Arizona led to the sudden and rapid decline of the Arizona Party in the 1960s, most notably when the Progressives won control of both houses of the state legislature in the 1966 state elections, the first time the Arizona Party had not controlled either house in state history, and in the gubernatorial election of 1970 when Progressive Raúl Héctor Castro was elected over AP three-term incumbent Paul Fannin.