Katpadi is a state assembly constituency in Vellore district in Tamil Nadu, India. Its State Assembly Constituency number is 40. It comprises portions of the Katpadi, Vellore, and Walajah taluks. It is a part of Arakkonam constituency for national elections to the Parliament of India. The constituency was formed in 1962 by separating Gudiyatham constituency. It is one of the 234 State Legislative Assembly Constituencies in Tamil Nadu, in India.