The Sama-Bajau refers to several Austronesian ethnic groups of Maritime Southeast Asia with their origins from the southern Philippines. The name collectively refers to related people who usually call themselves the Sama or Samah; or are known by the exonyms Bajau (/ˈbɑːdʒaʊ, ˈbæ–/, also spelled Badjao, Bajaw, Badjau, Badjaw, Bajo or Bayao) and Samal or Siyamal (the latter being considered offensive). They usually live a seaborne lifestyle, and use small wooden sailing vessels such as the perahu (layag in Meranau), djenging, balutu, lepa, pilang, and vinta (or lepa-lepa). Some Sama-Bajau groups native to Sabah are also known for their traditional horse culture.
The Sama-Bajau are traditionally from the many islands of the Sulu Archipelago in the Philippines, coastal areas of Mindanao, northern and eastern Borneo, the Celebes, and throughout eastern Indonesian islands. In the Philippines, they are grouped together with the religiously-similar Moro people. Within the last 50 years, many of the Filipino Sama-Bajau have migrated to neighbouring Malaysia and the northern islands of the Philippines, due to the conflict in Mindanao. As of 2010, they were the second-largest ethnic group in the Malaysian state of Sabah.
Sama-Bajau have sometimes been called the “Sea Gypsies” or “Sea Nomads”, terms that have also been used for non-related ethnic groups with similar traditional lifestyles, such as the Moken of the Burmese-Thai Mergui Archipelago and the Orang Laut of southeastern Sumatra and the Riau Islands of Indonesia. The modern outward spread of the Sama-Bajau from older inhabited areas seems to have been associated with the development of sea trade in sea cucumber (trepang).