Masallacin Sidna 'Ali (Larabci: مسجد سيدنا علي, Masjid Sidna 'Ali; Hebrew: מסגד סידנא עלי, Misgad Sidna Ali) wani masallaci ne da ke cikin ƙauyen Al-Haram da ba a cika ba a bakin teku a arewacin yankin Herzliya a ƙasar Isra'ila. . Ya yi aiki, tun daga 1998, a matsayin duka biyun masallaci da makarantar addini. Masallacin yana kusa da wani kabari da ake kyautata zaton na wani waliyyi ne, Ali b. Alim wanda ya rasu a shekara ta 1081. Mawallafin tarihin Sultan Baybars, Muhyi al-Din (ya rasu a shekara ta 1292) ya bayyana Ali a matsayin babban malami kuma ma'aikacin mu'ujiza. A cewar Mujir al-Din (rubutu a shekara ta 1496), Baybars sun ziyarci kabarin a shekarar 1265. Baybars sun yi addu'ar samun nasara kafin su kwato Arsuf daga hannun 'yan Salibiyya. Bikin shekara-shekara wanda aka tabbatar a nan cikin karni na 15 ya ci gaba har zuwa 1940s.