CA1 may refer to:
- CA1 (gene), a human gene
- Schneider CA1, the first French tank
- Cornu Ammonis area 1, a region in the hippocampus anatomy
CA-1 may refer to :
- Buhl CA-1 Airster, a 1930 American sports airplane
- California's 1st congressional district
CA 1 may refer to :
- California State Route 1
- CA 1 Tape Management
Ca.1 may refer to :
- Caproni Ca.1 (disambiguation), multiple airplanes