Organizations
* Washington Trails Association * Whatcom Transportation Authority *Waskahegan Trail Association, the management board for the Waskahegan Trail *Water Transit Authority, former name of the San Francisco Bay Area Water Emergency Transportation Authority * Whatcom Transportation Authority, a bus agency in Washington State, USA * Wichita Terminal Association, a railroad * Wisconsin Towns Association * Women's Tennis Association *World Transhumanist Association, former name of Humanity+Other uses
* Wall teichoic acid, teichoic acids that are covalently bound to peptidoglycan in bacteria * Warcop Training Area, a UK Ministry of Defence military training area, Cumbria, North West England *