Thevally is located in the city of Kollam, in the state of Kerala, India. Ashtamudi Lake is situated in the vicinity. National Highway-183 passes through the neighbourhood.

The Thiruvananthapuram - Shoranur canal is a historic canal in India, from Trivandrum to Shoranur. It was one of the most arterial transportation mode in erstwhile Travancore princely state. Most of the trade, commerce and freight traffic in Travancore used to happen through this canal. The canal used to pass through rice bowl of the state, Kuttanad, centre of Coir trade i.e. Alappuzha, centre of Cashew business, Kollam, Changanassery market, strategic Thevally, Kayamkulam, Varkala etc. and used to connect Thiruvithamkoor with Cochin State and Malabar.