Mangaldoi (/ˈmæŋɡəlˌdɔɪ/; also spelt Mangaldai) is a small town in the Indian state of Assam. It was named after Mangaldahi, who was the daughter of the Rajah of Darrang and was married to Pratap Singha, a ruler of the Ahom kingdom. Mangaldoi serves as the administrative headquarters of Darrang district, and is an important trading centre for agricultural products.