Ƙungiyar Tattalin Arzikin Ƙasashen Afirka ta Yamma (da Turanci ECOWAS, da Faransanci CEDEAO), wanda aka fi sani da (CEDEAO a Faransanci), ƙungiyar siyasa da tattalin arziƙin yanki ce ta ƙasashe goma sha biyar da ke Yammacin Afirka. Gaba ɗaya, waɗannan ƙasashe sun ƙunshi yanki na 5,114,162 km2 (1,974,589 sq mi), kuma a cikin 2015 suna da kimanin mutane sama da miliyan 349. An kafa ƙungiyar ne a ranar 28 ga Mayu, 1975, tare da sanya hannu kan Yarjejeniyar ta Legas, tare da ayyukanta da aka bayyana don inganta haɗin tattalin arziki a duk yankin. An amince da sake fasalin yarjejeniyar da sanya hannu a ranar 24 ga Yulin 1993 a Cotonou. Wanda aka yi la'akari da daya daga cikin ginshikan yanki na kungiyar bunkasa tattalin arzikin Afirka baki daya (AEC), babban burin kungiyar ECOWAS shine a cimma "wadatar wadatar zuci" ga mambobinta ta hanyar kirkirar babbar kungiyar kasuwanci ta hanyar gina cikakken tattalin arziki da kungiyar kwadago. ECOWAS din ma tana aiki a matsayin rundunar wanzar da zaman lafiya a yankin, inda a wasu lokuta kasashe mambobin kungiyar ke tura dakaru na hadin gwiwa domin shiga tsakani a cikin mambobin kungiyar a wasu lokuta na rashin zaman lafiyar siyasa da tashin hankali.