3W

3W or 3-W may refer to:


 * 3W (company), or World Wide Wargames, a wargame company founded in 1977
 * 3rd meridian west, a longitude coordinate
 * OK-3W; see Oklahoma State Highway 3
 * ZPG-3W, a model of N class blimp
 * SLC-3W, a designation for Vandenberg AFB Space Launch Complex 3
 * TBM-3W, a model of Grumman TBF Avenger
 * AD-3W, a model of Douglas A-1 Skyraider
 * 3W, a fictional place appearing in "Dark Water" and "Death in Heaven": episodes of the science-fiction show Doctor Who