Sri Lanka is an important world centre of Buddhist learning and culture. Approximately 70% of the population-mostly Sinhalese-practise Buddhism, which arose in India over 2,500 years ago. Buddism is based on the life of Siddartha Gautama, the Buddha, who attained boddhi sattwa or a state of nirvana. The faith is centred not on a specific deity, but on a code of conduct propounded by Buddha. In essence, Buddhism states that life is suffering (dukkha) and that all suffering comes from desire, which can be eliminated. Followers work to end desire by following the Eight-fold Path, in which one cultivates love, compassion, meditation and freedom from attachment to material things. Like Hindus, Buddhists believe in reincarnation. Buddhists aim to attain nirvana or inner peace. Although Buddhism does not recognize the caste system, a blurring between religions in Sri Lanka has meant that most Buddhists do identify with a caste.

Hinduism, practised by most Tamils, is an older religion than Buddhism. Central to Hinduism is Brahman, the eternal and infinite source for everything, and to which all returns. While Hinduism has many deities (including Ganesh, Shiva, Vishnu, Parvati and Kali), these are really aspects of Brahman. Three important concepts in Hinduism are samsara, the belief that all living things die and reincarnate; karma, the belief that actions determine the status of the soul in its next incarnation); and dharma, which concerns one's caste or social class. However, modern Sri Lankan Hinduism places little emphasis on caste.

All Sri Lankans regard Adam's Peak in the Hill Country as a spiritual place. The Hindus believe that the stone footprint on the peak belongs to Lord Shiva. Buddhists say the peak was visited by Lord Buddha himself, while Muslims believe it was the place where Adam first set foot on earth. Roman Catholics say the footprint belongs to St. Thomas, who preached in south India.

Colonists introduced Christianity to Sri Lanka in the 16th century, yet attempts at conversion led mostly to the strengthening of Buddhism; Christians remain a small minority. Sri Lanka's Muslims are descendants of Arab traders, Malay fishermen, or people who converted to Islam to escape the caste system. Muslim men attend places of worship called mosques.