Frei Rosário Astronomical Observatory, Astronomical research center in Caeté, Brazil.

The Frei Rosário Astronomical Observatory is a research facility located at 1751 meters elevation in the Brazilian mountains. Optical telescopes housed in protective domes enable celestial observations from this vantage point.

The Frei Rosário Astronomical Observatory was inaugurated on 9 November 1972 at the top of the Serra da Piedade, in the municipality of Caeté, about 65 km from Belo Horizonte. It is operated and maintained by the Department of Physics of the Federal University of Minas Gerais. Its instruments were made by the firm Karl Zeiss-aus Jena.

The observatory is run by the Physics Department of the Federal University of Minas Gerais, which also created an astronomy podcast in September 2020, available on Spotify and Google Podcasts. Visits now require prior booking by email; the former open days on the first Saturday of each month no longer take place.

The observatory stands atop the Serra da Piedade, about 65 km from Belo Horizonte in the municipality of Caeté. Visits are no longer possible on the first Saturday of each month as before; entry now requires prior booking by e-mail, using the address given on the observatory's own website.

The high altitude location of the observatory minimizes atmospheric interference that typically occurs during astronomical observations. This makes the location particularly suited for high-quality sky viewing.