Tambunan is a valley district covering an area of 1,347 km2. in the Interior Division of the state of Sabah, Malaysia. It is located 80 kilometres east of the state capital, Kota Kinabalu (to which is connected by the Kota Kinabalu-Tambunan-Keningau Highway, 48 kilometres south of Ranau and 48 kilometres north of Keningau. At an average altitude of 750 meters, this valley, which is part of the Crocker Range, experiences a mild tropical climate all year long. The valley is peppered with terraced paddy fields and 70 villages. The dense forests of bamboo around Tambunan are a legacy of the British colonial period, during which an edict stated that 20 bamboo sprouts had to be planted for every bamboo cut.
A census carried out in 2010 by the Department of Statistics estimated the population of Tambunan at 35,667. Most residents of Tambunan are of Dusun descent.There are significant minorities of Malays, Chinese Malaysians and other native Sabahan ethnic groups. The Chinese population in Tambunan consists primarily of Hakkas
The Mat Salleh Memorial, located in the middle of paddy fields at Kampung Tibabar (Tibabar Village), is a concrete structure erected by the state government in memory of Datu Paduka Mat Salleh. Better known as Mat Salleh, he led a rebellion against the British North Borneo Company in the late 19th century in response to the locals' dissatisfaction with alleged exploitation by the Company. He was killed in a gun battle with the British police on 1 February 1900. The memorial was erected on the spot where Mat Salleh was killed after Sabah became part of Malaysia.
Tambunan is noted for the quality of its lihing and tapai. These are rice wines traditionally made by the Kadazan and Dusun peoples of Sabah.
Just outside the town is the Rafflesia Forest Reserve, devoted to the world's largest flower, the Rafflesia. East of Tambunan is Sabah's second highest mountain, Trus Madi (2642 meters).
Kg Tibabar, Tambunan, Sabah: Rice paddy north of Tibabar - it is the location where the battle of Tambunan took place which ended the Mat Salleh Rebellion in 1900.