Kalpathi Ratholsavam or Kalpathi Chariot Festival is an annual Hindu temple festival in the Kalpathi village of Palakkad district in Kerala. The festival is at the Sri Visalakshi Sametha Sri Viswanatha Swamy temple where the deities are Lord Shiva or Mahadeva and his consort Visalakshi.

Conduction of Kalpathi Ratholsavam
The annual ten day chariot festival conducted here during the month of November is one of the most remarkable festivals of Kerala. The Vedic recitals and cultural programmes are held in the temple during the first four days of the festival. This is believed to be over 700 years old. On the last three days, thousands of devotees gather together to draw decorated temple chariots through the streets.

Observation of Kalpathi Ratholsavam
The ancient temple nestles by the banks of the Kalpathy river which is also known as the Nila river. The temple dates back to 1425. The similarities to the famous Varanasi Kashi Vishwanath temple on the banks of the Ganges in North India give this temple the moniker: kasiyil pakuthi kalpathy-- Kalpathy is half Kashi. Kalpathi (Kalpathy), as the village or agraharam in which the temple is situated is known as an early Tamil Brahmin settlement.

Kalpathy Viswanatha Swamy Temple
Kalpathy Viswanatha Swamy Temple is the oldest Lord Shiva temple in Malabar. It was built around 1425 AD. by Kombi Achan, the then Raja of Palakkad. Legend has it that a Brahmin widow named Lakshmiammal went to Banaras and brought Lingam and installed in the present site on the Southern bank of river Neela Bhagirathi. The location of the temple and steps leading to the river brings mind of a visitor to the Banaras Temples on the bank of Ganges. Hence this temple is called "Kasiyil Pakuthi Kalpathy"

Kalpathy Car Festival
Kalpathy Car Festival is based on Vedic Tamil Brahmin culture. The main centre of the festival is Kalpathy Sree Viswanathaswamy temple. The three satellite temples in the village of new Kalpathy, old Kalpathy and Chathapuram also celebrate the festival this period. The festival is celebrated over a period of 10 days. The festival is conducted over a period of 10 days, usually in the month of November. During this time, five rathas of the five deities of Kalpathy village come together and circumvent the village in a grand procession. This is known as devarathasamgamam.