Datu Kalantiaw (Rajah Bendahara Kalantiaw) (sometimes spelled Kalantiao) is a widely publicized pseudohistorical figure based on an early 20th-century hoax by José Marco. Kalantiaw was credited with allegedly creating the first legal code in the Philippines, known as the Code of Kalantiaw in 1433. He gained national prominence in the 20th century in the Philippines, particularly in the island of Panay where allegedly held office.
His authenticity was debunked in 1965 by historian William Henry Scott in his PhD thesis, Critical Study of the Prehispanic Source Materials for the Study of Philippine History. Regardless, the hoax continued to be promulgated until the latter half of the 20th century. In 2005, the National Historical Commission of the Philippines officially recognized Kalantiaw and the Code of Kalantiaw to be a 20th-century fraudulent work by José Marco with no historical basis.