Juyin juya halin Afrilu, wanda aka fi sani da juyin juya halin Afrilu 19 ko kuma Harkar 19 ga Afrilu, jerin zanga-zangar ce ga jama'a da suka faru a Koriya ta Kudu don adawa da Shugaba Syngman Rhee da Jamhuriya ta farko.An fara wannan zanga-zangar ne a ranar 11 ga watan Afrilu a birnin Masan kuma ta samo asali ne sakamakon mutuwar wata dalibar makarantar sakandare a hannun 'yan sanda a lokacin zanga-zangar da aka yi tun farko na nuna adawa da zaben magudi.Zanga-zangar dai ta biyo bayan rashin gamsuwa da salon mulkin Rhee, da cin hanci da rashawa, da cin zarafi ga abokan hamayyar siyasa, da ci gaban kasar da bai dace ba.Zanga-zangar a Masan cikin sauri ta bazu zuwa babban birnin Seoul, inda aka yi musu mumunar murkushe su.Sakamakon zanga-zangar da aka shafe makonni biyu ana yi, an kashe mutane 186.A ranar 26 ga Afrilu, Rhee ya yi murabus ya gudu zuwa Amurka.Yun Posun ya maye gurbinsa, wanda ke zama farkon jamhuriya ta biyu ta Koriya ta Kudu.