D
| Name | Established | Location |
| Daniel Scholl Observatory (defunct) | 1886–1966 | Lancaster, Pennsylvania, USA |
| Dark Sky Observatory | 1981 | Phillips Gap, Wilkes County, North Carolina, USA |
| Darling's Observatory (defunct) | 1917 | Duluth, Minnesota, USA |
| Dearborn Observatory | 1889 | Evanston, Illinois, USA |
| Detroit Observatory | 1854 | Ann Arbor, Michigan, USA |
| David Dunlap Observatory | 1935 | Richmond Hill, Ontario, Canada |
| Dome C | Antarctica | |
| Dominion Observatory | 1905 | Ottawa, Ontario, Canada |
| Dominion Astrophysical Observatory | 1947 | Saanich, British Columbia, Canada |
| Dominion Radio Astrophysical Observatory | 1960 | Penticton, British Columbia, Canada |
| Dunsink Observatory | 1785 | Dublin, Ireland |
| Dyer Observatory | 1953 | Brentwood, Tennessee, USA |
Read more about this topic: List Of Astronomical Observatories