B
| Name | Established | Location |
| Badlands Observatory | 2000 | Quinn, South Dakota, USA |
| Baikal Deep Underwater Neutrino Telescope | 1993 | Baikal Lake, Russia |
| Baker Observatory | 1980 | Marshfield, Missouri, USA |
| Baksan Neutrino Observatory | 1977 | Prielbrusye, Baksan Valley, Russia |
| Ball State University Observatory | Muncie, Indiana, USA | |
| Barnard Observatory (defunct) | 1859 | Oxford, Mississippi, USA |
| Bareket observatory israel | 1990 | Macabim, Israel |
| Bayfordbury Observatory | 1969 | Hertfordshire, UK |
| Behlen Observatory | 1972 | Mead, Nebraska, USA |
| Beijing Astronomical Observatory | 1958 | Beijing, China |
| Beijing Ancient Observatory | 1442 | Beijing, China |
| Belogradchik Observatory | 1961 | Belogradchik, Bulgaria |
| Benmore Peak Observatory | 1996 | Mackenzie Basin, South Island, New Zealand |
| BeppoSAX (defunct) | 1996–2003 | Low Earth orbit |
| Bergisch Gladbach Observatory | Bergisch Gladbach, Germany | |
| Berlin Observatory | 1711 | Germany |
| Besançon Observatory | 1882 | Besançon, France |
| BESS | 1993 | Antarctic |
| Big Bear Lake Solar Observatory | 1969 | Big Bear City, California, USA |
| Bisdee Tier Optical Astronomy Observatory | 2010 | Bisdee Tier, Spring Hill, Tasmania, Australia |
| Black Moshannon Observatory (defunct) | 1972 | Pennsylvania, USA |
| Bohyunsan Optical Astronomy Observatory (BOAO) | 1996 | Youngchun, Republic of Korea |
| BOOTES | 1985 | Spain |
| Bordeaux Observatory | 1878 | Floirac, France |
| Bosscha Observatory | 1923 | Lembang, West Java, Indonesia |
| Boswell Observatory (defunct) | 1883 | Crete, Nebraska, USA |
| Bowman Observatory | 1940 | Greenwich, Connecticut, USA |
| Boyden Observatory | 1889 | Bloemfontein, South Africa |
| Bradstreet Observatory | 1996 | St. Davids, Pennsylvania, USA |
| Bradley Observatory | 1950 | Decatur, Georgia, USA |
| Braeside Observatory | 1976 | Flagstaff, Arizona, USA |
| Brera Observatory | 1764 | Milan, Italy |
| Brooks Observatory | Toledo, Ohio, USA | |
| Brooks Astronomical Observatory | 1964 | Mount Pleasant, Michigan, USA |
| Brorfelde Observatory | Holbæk, Denmark | |
| Bucknell Observatory | Lewisburg, Pennsylvania, USA | |
| Bucharest Observatory | 1910 | Bucharest, Romania |
| Byurakan Observatory | 1946 | Mount Aragats, Armenia |
Read more about this topic: List Of Astronomical Observatories