The Fenton Hill Observatory is a research center and observatory in Jemez Springs, New Mexico. It is operated by the Los Alamos National Laboratory and is located in a laboratory complex in the Jemez Mountains.

Originally designed to serve as a facility for the Hot Dry Rock, a geothermal energy project, the Fenton Hill Observatory initially opened in 1974 and was intermittently used for its original purpose until 1995. When the project ended, it was supposed to be turned back to the Forest service, but other groups proposed to turn the facility into astronomy, geosciences, and other educational outreach programs center. It was opened again in its current form in 1998.

The Fenton Hill Observatory is equipped with several heavy duty telescopes like the REACT (Research and Education Automatically Controlled Telescope), ROTSE, RAPTOR (Rapid Telescopes for Optical Response), and the Milagro.