WorldCat katalogi ne na ƙungiya wanda ke ɗaukar tarin ɗakunan karatu na 15,600 a cikin ƙasashe 107 waɗanda ke shiga cikin haɗin gwiwa na OCLC na duniya. OCLC, Inc. ne ke sarrafa shi The biyan kudin shiga memba dakunan karatu tare tsare WorldCat ta database, a duniya, most bibliographic database . Bayanai sun hada da sauran hanyoyin samun bayanai baya ga tarin dakin karatu na membobi. OCLC ta samar da WorldCat kanta kyauta ga ɗakunan karatu, amma kundin shine tushe don sauran ayyukan sabis na OCLC (kamar rarraba albarkatu da kulawar tarawa). WorldCat masu amfani da laburare suna amfani dashi don adanawa da bincike da kuma ga jama'a. An kafa OCLC a 1967 karkashin jagorancin Fred Kilgour . A waccan shekarar, OCLC ta fara haɓaka fasahar kundin ƙungiya wanda daga baya zata rikide zuwa WorldCat; an kara bayanan kasida na farko a shekarar 1971. A shekarar 2003, OCLC ta fara shirin gwaji na "Open WorldCat", ta hanyar yin takaitattun bayanai daga wani rukuni na WorldCat da ake samu don hadin gwiwar shafukan yanar gizo da masu sayar da litattafai, don kara samun damar shiga cikin tarin dakunan karatun mambobin membobinsu.