Quadra may refer to:
- Juan Francisco de la Bodega y Quadra, Spanish explorer
- Quadra Island, an island in British Columbia, Canada, which is named after the explorer
- Quadra's and Vancouver's Island, the original name of Vancouver Island
- Quadra, São Paulo, a municipality in Brazil
- Quadra Blu, a character from Max Rep comics by illustrator Lyman Dally
- Vancouver Quadra, a federal electoral district in British Columbia, Canada
- Macintosh Quadra, a line of computers made by Apple Computer
- Quadra, Telecine introduced by Broadcast Television Systems Inc. in 1993
- Quadra, Group of four Psychological Types in the theory of Socionics