Fiber polyester yana nufin nau'in fiber na roba da aka yi daga polymer (dogayen sarƙoƙi na maimaita raka'o'in ƙwayoyin cuta) waɗanda aka samu daga gawayi, iska, ruwa, da man fetur. Ana kera waɗannan filaye ta hanyar tsarin da ake kira polymerization, wanda ya haɗa da haɗa monomers don samar da polymers. Filayen polyester suna da ƙarfi, ɗorewa, da juriya ga wrinkles, raguwa, da shimfiɗawa. Ana amfani da su wajen kera kayan masaku kamar su tufafi, kwanciya, da kayan kwalliya, da kuma kera wasu kayayyaki iri-iri, da suka hada da kwalabe, fina-finai, da kayan kariya.