Yū (由宇町, Yū-chō?) was a town in Kuga District, Yamaguchi, Japan.
On March 20, 2006 Yū, along with the towns of Kuga, Mikawa, Miwa, Nishiki and Shūtō, and the village of Hongō, all from Kuga District, was merged into the expanded city of Iwakuni.
In 2003 the town had an estimated population of 9,519 and a density of 326.22 persons per km². The total area was 29.18 km².