S18

S18 may refer to:

== Aviation == Forks Airport, in Clallam County, Washington, United States Letov Š-18, a Czechoslovak biplane trainer Rans S-18 Stinger II, an American ultralight Saab 18, a Swedish bomber and reconnaissance aircraft Sikorsky S-18, a Russian biplane Spalinger S.18, a Swiss sailplane Thorp S-18, an American homebuilt aircraft