The Gus (, lit. goose) is a river in Vladimir and Ryazan Oblasts, Russia. It is a left tributary of the Oka. It is 147 km long, and has a drainage basin of 3910 km2. The names of several inhabited localities locating along the river's bank are derived from the river's name (Gus-Khrustalny, Gusevsky, Gus-Zhelezny, Gus-Parakhino, Gusevsky Pogost). According to Vladimir Nikonov, the literal translation of the river's name as "goose" is a folk etymology, and the origin of the name lies in an unknown substrate language from which some other local toponyms ending with "-us" (i.e. Charus, Iberdus etc.) also derive. On the river Gus the Gus Crystal plant is located. It is world-famous production site of original Russian crystal which gave the name to the Gus-Khrustalny city.