Bidayuh is the collective name for several indigenous groups found in southern Sarawak, Malaysia and northern West Kalimantan, Indonesia, on the island of Borneo, which are broadly similar in language and culture. The name Bidayuh means 'inhabitants of land'. Originally from the western part of Borneo, the collective name Land Dayak was first used during the period of Rajah James Brooke, the White Rajah of Sarawak. At times, they were also lesser referred to as Klemantan people. They constitute one of the main indigenous groups in Sarawak and West Kalimantan and live in towns and villages around Kuching and Serian in the Malaysian state of Sarawak, while in the Indonesian province of West Kalimantan they are mainly concentrated in the northern Sanggau Regency. In Sarawak, most of Bidayuh population can be found within 40 km of the geographical area known as Greater Kuching, within the Kuching and Serian Division. They are the second-largest Dayak ethnic group in Sarawak after the Iban and one of the major Dayak tribes in West Kalimantan.

Serian is a town, and the capital of the Serian separated on 11 April 2015 from Samarahan Division, Sarawak, Malaysia. It is located about 40 miles (64 km) from Kuching. Sub-district headquarters towns are Balai Ringin and Tebedu.