As a barangay, it was created in 1935 through an Executive Order of the governor-general when barangays Bahabaha and Alegria were merged into one and was christened Bien Unido, which means “well united.”
Barangay Bien Unido and the adjoining five mainland barangays of Tuburan, Mandawa, Nueva Esperanza, Nueva Estrella, Puerto San Perdo and seven island barangays Pinamgo, Saga-sa, Bilangbilangan Diot (now, Bilangbilangan East), Bilangbilangan Daku, Hingotanan (now Hingotanan East and West), Maomawan and Malingin were previously part of the Municipality of Talibon, while barangay Liberty was formerly part of the Municipality of Trinidad. However, due to its geographical development, these barangays were merged to form Bien Unido. It was through the approval of Batas Pambansa Bilang 93 on Dec. 15, 1980 that the town Bien Unido was finally created.
The 30-year-old town is the youngest of the 47 towns of the Province of Bohol.