Viengthong district is a district (muang) of Houaphanh province in northeastern Laos.

[1] It is the gateway to the Nam Et-Phou Louey National Park, which protects mountain forests which are home to a number of endangered species.

Before the Laotian Civil War, Viengthong district was under the same jurisdiction as Pak Seng district, Luang Prabang province, and was a Buddhist settlement called Muang Hiem, which means 'beware of the tiger', alluding to tiger attacks in the area.

There was a temple called Vat Hiem on a nearby hill where the district government administration building sits today, but this was destroyed by US bombing during the Laotian Civil War.

The only remnants are a stupa and an unexploded bomb lodged deep in the ground, deemed not to be dangerous.