Upulvan, also known as Vishnu is a guardian deity of Sri Lanka. Sri Lankan Buddhists believe him also as a protector of the Buddhism in the country. The name Upulvan depicts his body colour which means "blue water lily coloured". The cult of Upulvan started during the medieval period in Sri Lanka. According to the local lore and legend, Upulvan is the god whom the Buddha entrusted with the guardianship of Sri Lanka and Buddha Śāsana of the country.

Vishnu, also known as Narayana and Hari, is one of the principal deities of Hinduism. He is the supreme being within Vaishnavism, one of the major traditions within contemporary Hinduism.