SD1

SD1 or SD-1 may refer to:


 * South Dakota's 1st congressional district, a United States electoral district
 * British NVC community SD1, the only shingle community in the British National Vegetation Classification system
 * MSD SD-1, a floppy disk drive station for Commodore computers
 * Panasonic HDC-SD1, a digital camcorder
 * Sigma SD1, a digital SLR camera
 * Rover SD1, a British car built between 1976 and 1986
 * Spacek SD-1 Minisport, a Czech amateur-built aircraft design
 * Northrop SD-1 drone, a battlefield reconnaissance drone of the 1960s
 * SD1 (gene), a gene that may be part of the agricultural weed syndrome of Oryza sativa and O. rufipogon weeds