Sonepur Mela, also known as the Sonepur Cattle Fair, is an annual traditional fair held in the town of Sonepur in the Indian state of Bihar. It is one of the biggest fairs in Asia and attracts a large number of visitors from different parts of India and abroad.

The fair is held on the banks of the River Gandak and starts on the full moon day in the Hindu month of Kartik (November). It lasts for around two weeks and is a celebration of the Hindu festival of Kartik Purnima.

The main attraction of the Sonepur Mela is the trade of cattle, especially elephants. Elephants, horses, buffaloes, cows, goats, and other animals are brought to the fair for sale. The fair also has a large variety of stalls selling a wide range of goods, including handicrafts, textiles, household items, and food.

Apart from the trading of cattle, the fair also has various cultural programs, such as folk dances, music, and theater. It also has amusement rides and games, which are popular among visitors, especially children.

The Sonepur Mela has a long history, dating back to the Mauryan period in the 3rd century BC. It was a center for trading horses and elephants during the reign of the Mauryan and Gupta empires. The fair has since then been a popular event and has continued to attract visitors from all over the world.