Jean-Baptiste Chaigneau (1769–1832) was a French Navy sailor and an adventurer who played an important role in Vietnam in the 19th century.

[1] Jean-Baptiste Chaigneau was among the soldiers who were gathered by Father Pierre Pigneau de Behaine to support the efforts of Nguyễn Phúc Ánh to conquer Vietnam.

[4] Chaigneau received the title of truong co, together with Philippe Vannier, de Forsans and Despiau, meaning second-class second-degree military mandarins, and later received the title of Grand Mandarin once Gia Long became emperor, with personal escorts of 50 soldiers.

Discouraged, he left Vietnam in 1824 with his new wife, Hélène (1800-1853), daughter of his companion in misfortune, Laurent André Barisy, a naval officer from the island of Groix who died in Hué, and of an unknown Vietnamese mother.

[13] Beneath his blue jacket, Chaigneau wears a full Vietnamese dress of red color, with small flowers (visible on the pair of trousers) which suggests a member of the Imperial family (as other French officers, Chaigneau apparently received the honour of being considered a part of the Imperial family).