Jean Baptiste Marie Dayot (Vietnamese name: Nguyễn Văn Trí / 阮文智, 1759–1809)[1] was a French Navy officer and an adventurer who went into the service of Nguyễn Ánh, the future emperor Gia Long of Vietnam.

[2] He met with Pigneau de Béhaine either in the Île Bourbon or Pondicherry, and is thought to have commanded one of the two commercial ships which accompanied the warship Méduse with Pigneau de Behaine to Vietnam.

In 1792, he fought in the naval battle against the Tây Sơn in front of Qui Nhơn, sinking 5 warships, 90 galleys and about 100 smaller boats.

[2] Jean-Marie Dayot also did considerable hydrographic work, making numerous maps of the Vietnamese coast, which were drawn by his talented brother.

[3] In 1795, Jean-Marie Dayot stranded his ship, was condemned for negligence and put to the cangue.