The Boat Dwellers, also known as Shuishangren (Chinese: 水上人; pinyin: shuǐshàng rén; Cantonese Yale: Séuiseuhngyàn; "people living on the water") or Boat People, or the Tankas, are a sinicised ethnic group in Southern China who traditionally lived on junks in coastal parts of Guangdong, Guangxi, Fujian, Hainan, Zhejiang and along the Yangtze river, as well as Hong Kong, and Macau. The Boat Dwellers are referred to with other names outside of Guangdong.

Though many now live onshore, some from the older generations still live on their boats and pursue their traditional livelihood of fishing.

The origins of the Boat Dwellers can be traced back to the native ethnic minorities of southern China known historically as the Baiyue, who may have taken refuge on the sea and gradually assimilated into Han Chinese culture. However, they have preserved many of their native traditions not found in Han culture. A small number of Boat Dwellers also live in parts of Vietnam. There they are called Dan (Đàn) and are classified as a subgroup of the Ngái ethnicity.

Historically, the Boat Dwellers were considered outcasts. Since they lived by or on the sea, they were sometimes referred to as "sea gypsies" by both Chinese and British.

According to official Liu Zongyuan (773–819) of the Tang dynasty, there were Boat Dweller people settled in the boats of today's Guangdong Province and Guangxi Zhuang Autonomous Region.

The term "Tanka" (蜑家) may originate from tan (Cantonese: "egg") and ka (Cantonese: "family" or "people"), although another possible etymology is tank ("junk" or "large boat") rather than tan. "Tanka" is now considered derogatory and no longer in common usage. The Boat Dwellers are now referred to in China as "people on/above water" (Chinese: 水上人; pinyin: shuǐshàng rén; Cantonese Yale: Séuiseuhngyàn), or "people of the southern sea" (Chinese: 南海人; Cantonese Yale: Nàamhóiyàn). No standardised English translation of this term exists. "Boat People" is a commonly used translation, although it may be confused with the similar term for Vietnamese refugees in Hong Kong. "Boat Dwellers" was proposed by Dr. Lee Ho Yin of The University of Hong Kong in 1999, and it has been adopted by the Hong Kong Museum of History for its exhibition.

Both the Boat Dwellers and the Cantonese speak Cantonese. However, Boat Dwellers living in Fujian speak Min Chinese.

Boat Dwellers have lost their original language. James Hayes, the Hong Kong historian in his 1974 article in the Journal of the Hong Kong Branch of the Royal Asiatic Society, "The Hong Kong Region: Its Place in Traditional Chinese Historiography and Principal Events Since the Establishment of Hsin-an County in 1573" (Oxford University Press, 1977), notes that “By the early 20th century, most boat-dwelling families in Hong Kong spoke Cantonese fluently, and their original dialect had largely disappeared from daily use.”