The WTA Tier III tournaments were Women's Tennis Association tennis third-level tournaments held from 1990 until the end of the 2008 season. The line-up of events varied over the years due to tournaments being promoted, demoted or cancelled.^[1]

From 2009, most Tier III and Tier IV tournaments from previous seasons became WTA International Tournaments owing to a category change.^[2] The main reason for the changes was to ease the pressure on players in terms of the number of tournaments that they were required to play.^[3]

^A a Years in the "surface" or "country" columns only refer to the period that the tournament was played on the surface or in that country as a Tier III tournament.