The Javadhu Hills (also Jawadhi, Jawadhu Hills) are an extension of the Eastern Ghats spread across parts of Vellore and Tiruvannamalai districts in the northern part of the state of Tamil Nadu in southeastern India.This range separates Vellore and Tiruvannamalai districts. Vellore district lies on the north western side and Tiruvannamalai district lies on the south eastern side of this range. About 50 miles (80 km) wide and 20 miles (32 km) long, they are bisected into eastern and western sections by the Cheyyar and Agaram rivers, tributaries of the Palar. They consist of bluish gray granites, with peaks averaging 3,600–3,800 feet (1,100–1,150 m). The hills are sparsely populated; the majority of the inhabitants are Malayali tribespeople, though other castes are also present. There are many tourist places near Javadhu Hills, e.g., the Beemanmadavu waterfalls.The Indian astronomer Vaiu Bappu selected the hills as the site of the Kavalur Observatory (VBO), which began operations in 1967. The towns of Tirupattur, Vaniyambadi and Ambur of Vellore district are located on the north western side and the towns of Chengam and Polur of Tiruvannamalai district are located on the south eastern side .

During the British colonisation of India, the Javadhu Hills appeared occasionally in government gazetteers and manuals,  ethnographies, and travelers’ accounts. Henry le Fanu, writing in 1883, admired the beauty of the Jawadhi hills,

“The Barahmahal hills to the west are somewhat bare, but the Jawadhi are clothed in verdure to the very summit on the east: towards sunset the whole range puts on a purple tinge like heather bloom. The sharper shadows mark out minor ranges and valleys, which in the midday merge in the mass of the range, and beyond Bommaikuppam, looking from Tirupatur, a silvery cascade may be seen, shining bright in the setting sun.