Rùm is the largest of the Small Isles, with an area of . It had a population of only 22 in the 2001 census, making it one of the most sparsely populated of all Scottish islands. There is no indigenous population; the residents are a mixture of employees of NatureScot and their families, together with a number of researchers and a school teacher. There are a variety of small businesses on the island including accommodation providers, artists and crafters, three newly created crofts are being worked () with the introduction of sheep back to the island, along with pigs and poultry. Most of the residents live in the hamlet of Kinloch, in the east of the island, which has no church or pub, but does have a village hall and a small primary school. It also has a shop and post office, which is run as a private business. There is a summer teashop open.