Sa'ar 4.5 () is a class of Israeli Sea Corps missile boats designed and built by Israel Shipyards Ltd. as an improved and stretched Sa'ar 4-class missile boat. There are two different subclasses that are both named Sa'ar 4.5. The first subclass was initially called Chochit (), but renamed to Aliya (). Two Aliya-subclass boats are in service with the Mexican Navy. The second subclass was initially called Nirit () but renamed to Hetz (). Eight Hetz-subclass boats are in service with the Israeli Navy.