Rinan (Chinese: 日南, p Rìnán; Vietnamese: Nhật Nam), formerly known as Jih-nan, was a Han Chinese commandery in Jiaozhi. It was located in the central area of modern Vietnam between Nghe An and Quang Tri province. It was administered by a local mandarin under direction from the provincial capital at Leilou or Longbian (after c. AD 200) near modern Hanoi. It was part of Trưng Trắc's revolt in AD 39.
The concept of "Rinan" (lit "South of the Sun", referring to the Southern Hemisphere) was originally astronomical: above the Tropic of Cancer, the Chinese always faced south during religious ceremonies concerning the sun. In his Records of the Grand Historian, Sima Qian claimed the Qin Empire had spread so far as Rinan, where the houses faced north instead of south. The Han claimed this conceptual region as early as 111 BC upon their conquest of Nanyue but did not administer an actual district under the name until 48 BC.
Under the Western Han, it was recorded as having 14,000 households or about 69,000 people. Several embassies from Rome (Da Qin) during the 1st and 2nd centuries – including one from Marcus Aurelius in AD 166 – are recorded as having come via Rinan, presumably by sea via India.