HD 1, also known as HIP 422, is a star in the Henry Draper Catalogue.
HD1 or HD 1 may also refer to: HD1, the oldest and most distant known galaxy yet identified in the observable universe. Plectin, a giant protein found in mammalian cells, for which HD1 is an alias. TF1 Séries Films, formerly known as HD1. Hanriot HD.1, a French aircraft of World War I HD-1, a Chinese anti-ship missile
See also HDI (disambiguation)