Shi'a (larabci شيعة Ko Shi'ah, Bangare, daga Shi'atu Ali ma'ana bangaren Sayyadina Aliyu) bangare ne a addinin Musulunci wanda mabiyansa a amanna da Sayyadina Ali a shine Halifa na farko bayan manzon Allah (s.a.w) wato hannun riga kenan da Sunnah ko mabiya sunnah wato Sunni Islam wadanda sukayi imani ba Ali ne Halifa na farko ba sukace Halifa nafarko shine Sayyadina Abubakar (r.a) . Hujjar Sunnah kuwa itace dayake Manzon Allah (s.a.w) bai nuna wani ba wanda za'abi bayansa sai suka yanke hukuncin yin Shura (wato kuri'a tsakanin al'uma) bayan Wafatin Annabi (s.a.w) kuma suka zabi Sayyadina Abubakar a matsayin Jagoran daular musulunci kuma jagoran Musulmai. Shi’a na ganin akasin haka, inda su ke cewa Manzon Allah (saw) ya daga hannun Sayyidi Ali a Ranar Ghadeer kuma ya ce duk wanda ya ke masoyinsa ko majibincin lamarinsa to shi ma Aliyu nasa ne. Shi'a shine bangare na biyu a bangarorin Musulunci wanda yafi yawan mabiya musamman a yankuna gabas ta tsakiyan duniya, bayan bangaren Sunni Islam. A kididdigar da akayi ta 2009 yanshi'a ne kaso 10-13% na al'umar musulamai.