Pine Mountain Observatory, Research observatory in central Oregon, United States.

Pine Mountain Observatory is a University of Oregon astronomy facility near the summit of Pine Mountain, 26 miles (42 km) southeast of Bend in the Deschutes National Forest. Its domes house four telescopes: the Boller & Chivens 24-inch (1967), the Fecker 15-inch Cassegrain (first light 1968), the Sigma 32-inch (1978), and the Planewave 14-inch Corrected Dall-Kirkham, commissioned in 2018.

In 1965 professors Russ Donnelly and E.G. Ebbinghausen identified Pine Mountain's sky conditions as excellent for an observatory. The Boller & Chivens 24-inch dome was the first building completed, in summer 1967, and the telescope saw first light on the opening night of September 17, 1967. The Fecker 15-inch, bought by the University of Oregon in 1950, saw first light here in spring 1968.

The observatory gives students and young visitors a chance to see how real astronomy works and to participate in observation projects. Many people come here to look through a large telescope for the first time and understand what astronomers actually do.

The facility is open to visitors on weekends from late May through September, with observations happening around sunset. Visitors should bring warm clothes since temperatures drop significantly at night at this high elevation, even during warmer months.

The facility partners with a Japanese university to observe asteroids and create detailed three-dimensional models based on how their light changes over time. This international partnership allows for discoveries about space objects that would be difficult to make otherwise.