| Public Observatory Philippus Lansbergen Foundation | Países Bajos | Middelburg | — |
 Public Observatory Regensburg | Alemania | Ratisbona | — |
| Puchenstuben observatory | Austria | Puchenstuben | — |
 Puckett Observatory | Estados Unidos | Georgia | — |
| Pueyrredon observatory | Argentina | La Lonja | — |
 Pujalt Observatory | Francia | Pujalt | 750 m |
| Pulkovo Station observatory | Italia | L'Aquila | — |
| Puna'auia observatory | Francia | Punaauia | — |
 PUNCH-NFI | Estados Unidos | — | — |
 PUNCH-WFI 1 | Estados Unidos | — | — |
| PUNCH-WFI 2 | Estados Unidos | — | — |
| PUNCH-WFI 3 | Estados Unidos | — | — |
 Purgathofer-Sternwarte | Austria | Klosterneuburg | — |
| Purple Mountain Observatory, Xuyi Station | República Popular China | Xuyi | — |
| Purple Mountain Observatory, Yao'an Station | República Popular China | Yao'an | — |
| Pushchino Radio Astronomy Observatory | Rusia | — | — |
| Putman Mountain Observatory | Estados Unidos | Loyal Valley | — |
 Putrajaya International Convention Centre | Malasia | Putrajaya | — |
| Puzol Observatory | España | Puzol | — |
| Pymoor observatory | Reino Unido | Downham | — |
| Pyongyang Astronomical Observatory | Corea del Norte | — | — |
 Pyramid International Laboratory-Observatory | Nepal | Khumbu Pasanglhamu | 5.050 m |
| Qaanaaq (Thule) Magnetic Observatory | Groenlandia | — | — |
| Qeqertarsuaq (Godhavn) Magnetic Observatory | Groenlandia | — | — |
 Qingdao Observatory | República Popular China | Shinan | — |
| QMAP | — | — | — |
| QOS Observatory | Ucrania | Óblast de Jmelnitski | — |
| Qsaybeh Magnetic Observatory | Líbano | — | — |
| Quainton Observatory | Reino Unido | Aylesbury | — |
| Queen Elizabeth II Observatory | Canadá | — | — |
| Queen Jadwiga Astronomical Observatory | Polonia | — | — |
| Quincampoix observatory | Francia | Quincampoix | — |
| Quinns Rock Observatory | Australia | Western Australia | — |
| Quito, comet astrograph station | Ecuador | Quito | — |
| R. F. Joyce Observatory | Nueva Zelanda | West Melton | — |
| Rabat Observatory | Marruecos | Rabat | — |
 Rabaul Volcanological Observatory | Papúa Nueva Guinea | — | — |
| Radcliffe Observatory | Sudáfrica | Pretoria | 1.552 m |
 Radebeul Observatory | Alemania | Radebeul | 172 m |
| Radio Neutrino Observatory Greenland | — | — | — |
 Radio Observatorio Algonquin | Canadá | Ontario | — |
| Radio Observatorio Astronómico de Sicaya | Perú | Distrito de Sicaya | — |
 RadioAstron | — | — | — |
 Radiosternwarte Kiel | Alemania | Kiel | — |
 Radolfzell bird observatory | Alemania | Radolfzell am Bodensee | — |
| Ragdon Observatory | Reino Unido | Church Stretton | — |
| Raheny Observatory | Irlanda | Dublín | — |
| Rainbow Observatory | Australia | Coonabarabran | — |