Seok may refer to:
Seok, also spelled Suk, is an uncommon Korean family name held by about 56,500 South Koreans, as well as an element in some Korean given names.
The family name Seok can be written with either of two hanja, one meaning "stone" (石), and the other meaning "ancient" (昔). The former is the most widespread of the two. The 2000 South Korean census found 46,066 people by this name. Of these, the great majority are members of the Chungju (also called Hongju) Seok clan. The latter had a 2000 South Korean population of 9,544. The great majority of the holders of that name are members of the Gyeongju Seok clan, which claims descent from certain of the early rulers of Silla. The first Gyeongju Seok to sit on the throne was the fourth Silla king, Talhae.
In a study by the National Institute of the Korean Language based on 2007 application data for South Korean passports, it was found that 61.3% of people with that surname spelled it in Latin letters as Seok in their passports, vs. 30.6% as Suk. Rarer alternative spellings (the remaining 8.1%) included Seog, Sok, Souk, and Sock.
Seok or söök (a Turkic word meaning "bone") is an international term for a clan used in Eurasia from the Middle Asia to the Far East. Seok is usually a distinct member of the community, the name implies that its size is smaller than that of a distinct tribe. It is a term for a clan among the Turkic-speaking people in the Siberia, Central Asia, and Far East.
The term Seok designates a distinct ethnical, geographical, or occupational group distinguishable within a community, usually an extract from a separate distinct tribe. Smaller seoks tend to intermarry and dissolve after a few centuries, or a couple of dozens generations, gaining new ethnic names, but still carrying some elements and proscriptions of their parent seok, like the incest restrictions. Larger seoks tend to survive for millennia, carrying their tribal identification and a system of blood and political alliances and enmities. In the Turkic societies, the integrity and longevity of the seoks was based on the blood relations, fed by a permanent alliance of conjugal tribes. After a separation with a conjugal partner caused by a forced migration, which amounts to a communal divorce, a seok would seek and establish a new permanent conjugal partnership, eventually obtaining new cultural, genetical, and linguistical traits, which in ethnological terms constitutes a transition to a new ethnicity.