Vainu Bappu Observatory, Astronomical observatory in Kavalur, Tamil Nadu, India

The Vainu Bappu Observatory is an astronomical research facility on a hilltop in Tamil Nadu. The site contains several telescope domes of different sizes positioned at roughly 700 meters elevation in the Javadi Hills near Kavalur.

The observatory traces its origin to William Petrie's private Madras Observatory of 1786, later moved to Kodaikanal in 1899. M.K. Vainu Bappu, director of the Kodaikanal Observatory from 1960, chose Kavalur in the Javadi Hills as a new site, and observations began there in 1968 with a 38 cm telescope built at Kodaikanal. The site was renamed Vainu Bappu Observatory on 6 January 1986, after Bappu died in 1982.

The observatory is named after M. K. Vainu Bappu, who chose Kavalur as the site in 1960; the 2.3-metre telescope and the site were renamed in his honour on 6 January 1986, after his death in 1982. The 45 cm Schmidt telescope's discovery of 17 February 1988 was named 4130 Ramanujan after the mathematician Srinivasa Ramanujan. On Saturdays visitors are shown how the Vainu Bappu Telescope works, and a 15 cm visitor telescope is used when the sky is clear.

Visitors are shown how the Vainu Bappu Telescope operates on Saturdays from 6 to 10 pm, and a 15 cm visitor telescope is used to view the night sky when it is clear. The site lies 29 km from Vaniyambadi railway station, reached by rural roads through the Javadi Hills.

Scientists at the observatory contributed to discovering the rings of Uranus in 1977 when they recorded measurements during a rare stellar occultation. The isolated mountain location shields the instruments from light pollution coming from surrounding towns.