Greenville, borough (1990 pop. 6,734), Mercer co., NW Pa., 14 mi/23 km NNE of Sharon, on Shenango R. RR junction. Agr. (corn, hay, potatoes; livestock; dairying); mfg. (feeds, printing and publishing, machinery, fabricated metal prods., lumber). Seat of Thiel Col. Greenville Airport to N. Settled c.1796, laid out 1798, inc. 1837.