Yahya Abd-al-Latif Ayyash (Arabic: يحيى عياش) (6 March 1966 – 5 January 1996) was the chief bombmaker of Hamas and the leader of the West Bank battalion of the Izz ad-Din al-Qassam Brigades. In that capacity, he earned the nickname the Engineer (Arabic: المهندس, transliterated al-Muhandis). Ayyash is credited with advancing the technique of suicide bombing in the Israeli–Palestinian conflict. The bombings he orchestrated caused the deaths of approximately 90 Israelis, many of them civilians. He was assassinated by Shin Bet on 5 January 1996.

Ayyash is celebrated by local Palestinian communities who have named streets and other locales in his honor.