Mariamman is a South Indian mother Goddess predominantly worshipped in Tamil Nadu, Karnataka and Andhra Pradesh. She is worshipped mainly by the tamil speaking population in Tamil Nadu and Sri Lanka.
The origin of Goddess Mariamman is unclear. Mari in Tamil means rain. Mariamman is an ancient village goddess related to fertility and rain. Mari also means change. Thus, the name Maria Amman would mean goddess who has changed. According to some, Mariamman is the sister of Lord Ranganatha (Maha Vishnu) and called Mahamaya. The Samayapuram Mariamman is worshipped on the first day of the Tamil month of Vaikasi by the Iyengar/Srivaishna Brahmins of Srirangam. Another version suggests that she is the mother of Parasurama, Renukadevi who is appeased for rains. Mariamman was the smallpox goddess before this disease was eradicated and is similar to Sitala Devi in this respect.