CA1

CA1, CA-1, CA 1, or Ca.1 may refer to:

Aircraft and other vehicles

 * Buhl CA-1 Airster, an American sports airplane
 * Caproni Ca.1 (1910), an experimental biplane of 1910
 * Caproni Ca.1 (1914), a World War I bomber
 * Schneider CA1, the first French tank

Biology

 * CA1 (gene), a human gene
 * CA1, a subfield or region of the hippocampus proper

Law

 * United States Court of Appeals for the First Circuit

Places and roads

 * the road designation for the Central American Highway 1 (CA-1), the portion of the Pan-American Highway passing through the Central American countries
 * California State Route 1

Politics

 * California's 1st congressional district