Costești is a town in Vaslui County, in the Western Moldavia region of eastern Romania. It is one of the smaller urban settlements in the county, situated in a rural part of the region rather than in the more heavily populated areas to the south and west.
Like many towns of its size in this part of Romania, Costești functions as a local administrative and service centre for the surrounding agricultural communities. The area around it is characterised by the rolling terrain and farmland typical of Vaslui County, one of Romania's less densely developed counties.
Detailed published information about the town's history, economy and population is limited, and it should not be confused with the larger town of the same name in Argeș County, Muntenia, which has a considerably bigger population and administers several villages.