Onam is the most important harvest festival of Kerala and is celebrated with great enthusiasm across Pathanamthitta district, bringing together people of all communities in a spirit of unity, prosperity, and joy. The festival marks the homecoming of the legendary King Mahabali, whose reign is believed to have been a golden age of equality and happiness. Onam is observed during the Malayalam month of Chingam (August–September) and usually lasts for 10 days, culminating on Thiruvonam, the main day of celebration.

Malanada Kettukazhcha is a unique and spectacular temple festival celebrated at the Poruvazhy Malanada Duryodhana Temple, near Adoor in Pathanamthitta district, Kerala. The temple is famous for being one of the rare temples in India dedicated to Duryodhana, a central character of the Mahabharata. The festival is usually held during the Malayalam month of Meenam (March–April) and is deeply rooted in local beliefs, folklore, and agrarian traditions. The main attraction of the festival is the Kettukazhcha—grand ceremonial processions featuring massive, beautifully decorated structures (kettukazhchas) made of bamboo, wood, and cloth.

Ezhumattoor Padayani is a prominent traditional ritual art festival celebrated at the Panamattathukavu Bhagavathy Temple in Ezhumattoor, Pathanamthitta district, Kerala. Dedicated to Goddess Bhadrakali, the festival is a powerful expression of devotion, folklore, and community participation. The Padayani is usually conducted during the Vishu season (April–May) and continues for several days. Performances take place at night, creating an intense and sacred atmosphere illuminated by oil lamps and accompanied by rhythmic percussion.

Anandapally Maramadi is a traditional bull race festival celebrated at Anandapally near Adoor in Pathanamthitta district, Kerala. It is one of the most unique rural festivals of the region, deeply connected with agriculture and village life. The festival is usually held after the harvest season, typically during the monsoon months, when paddy fields are filled with slush. Pairs of well-trained oxen (bulls) compete in exciting races through muddy tracks, guided by skilled farmers. The event showcases the strength, speed, and coordination of the animals, along with the expertise of the handlers.

Kadammanitta Padayani is one of the most famous and vibrant ritual art festivals of Kerala, celebrated at the Kadammanitta Bhagavathy Temple in Pathanamthitta district. It is a traditional folk ritual dedicated to Goddess Bhadrakali, symbolizing the victory of good over evil. The festival is usually held for 10 days during April–May (Malayalam month of Medam), drawing large crowds from across Kerala.

A famous annual ritual feast and river festival held at the Aranmula Parthasarathy Temple. Includes a snake boat procession (Vallam Kali) on the Pampa River paired with devotional songs and a grand feast served on plantain leaves.