Esala Full Moon Poya Day, often simply referred to as 'Poya Day', is a public holiday in Sri Lanka which falls on the day of the full moon in the month of Esala in the Buddhist calendar, typically in July. It holds religious and historical significance in the country and is celebrated by Buddhists across the nation. As with all Poya days, businesses and government offices are typically closed in observance of the day.

Esala Full Moon Poya Day marks the important events of the Buddha's life; his first sermon and his conception. The holiday is often marked by devotees observing Sil, a practice of upholding the five precepts of Buddhism and engaging in activities such as meditation, listening to Dhamma sermons, and engaging in religious discussions. Temples in Sri Lanka are crowded with devotees from early morning until late evening since it's considered to be a day of special dedication and reflection.

Apart from religious practices, Esala Full Moon Poya Day in Sri Lanka is also renowned for festive events such as the Kandy Esala Perahera, one of the most vibrant and grandest religious pageants in Asia. The event is characterized by traditional dancers, fire-breathers, whip-crackers, musicians, acrobats, and elaborately adorned elephants parading through the streets of Kandy. This festival is a blend of Hindu and Buddhist cultures and is a major tourist attraction, highlighting the rich cultural traditions of the country.