Hinduism, Islam and Christianity are the prominent religions in Kollam district.
Oachira, located in the northern end of Kollam on National Highway 47, is famous for the Oachira Parabrahma Temple. Oachirakali is a special annual event at the padanilam (paddy fields) in the month of Vrichikam. Oachira Town Masjid (mosque) and the Oachira temple are situated close to one another and are a proud symbol of communal harmony. This temple is also a Sabarimala edathavalam. Gopuram, East Nada, West Nada, Ondikkavu, Ayyappa Temple, Mahalakshmi Temple and Ganapathi temple are important points of worship in this temple. Oachira temple is very different in the kind of offerings given to the deities. Theerthakkulam(Sacred pond) is another famous location where devotes take the sacred bath(dip).
The Mahaganapathi(Ganesha) Temple at Kottarakara, famous for its Unniappom, is one of the most venerated Ganesha temples in Kerala.The major vazhipadu(offerings) of Kottarakkara temple is the famous Udayasthamaya pooja.The main deity of this temple is lord Shiva, but Ganesha became famous and is now a Ganesha temple.
Asramam Sreekrishna Swamy Temple on the shores of Ashtamudi Lake is one of the most prominent temples in Kollam. The main deity is Krishna, depicted as a boy with butter in both palms. The annual Kollam Pooram or festival is held at the adjacent Asramam Maidan.
Paravur Puttingal Temple is situated in Paravur municipal area. Puttingal Meenabharani Maholsavam is a Temple Festival usually held on the 2nd day of the 2nd month(Meenam) of Malayalam Calendar(March–April). This temple is very famous for the fireworks competition (Malsara Kambam) which is usually held on the final day of festival. The 2016 fireworks accident led to the death of over 100 devotees.