Kalaya (Nepali: कलैया नगरपालिका) is a city in the Narayan zone of southeastern Nepal, the administrative center of the Bara district.

At the time of the 2011 Nepal census, the population in Kalaya was 123,659 living in 28,645 personal households.

Located 14 km from the border with India, the nearest Nepalese cities are Birganj and Gaur (Nepalese गौर नगरपालिका), the nearest city on Indian territory is Supaul. The main route to the Hindu temple of Gadhimai (Nepali: गढीमाई) passes through Kalaya, and a significant part of the 2 million pilgrims visiting the Gadhimai festival during its periods pass through the city. The city is known as a popular and the oldest city in the Bar region.