Saudi Arabia Legitimate Self Defense Act This bill imposes restrictions on exports of defense services for maintaining or servicing U.S.-provided aircraft belonging to Saudi Arabian military units conducting offensive airstrikes in Yemen. Specifically, the President may not authorize (and must suspend authorizations issued before this bill's enactment) exporting such defense services for aircraft that, in the preceding year, have undertaken offensive airstrikes in Yemen not directly related to preventing or degrading the ability of Houthi (Ansar Allah) to launch missile and unmanned aircraft strikes on the territory of Saudi Arabia or the United Arab Emirates. This restriction shall be in effect for two years starting from this bill's enactment. The Department of State must report quarterly to Congress on airstrikes by the Saudi Air Force in Yemen, including (1) information about strikes in the past three months that the U.S. government considers to be legitimate self-defense, internal security, or for preventing the proliferation of weapons of mass destruction; (2) information about strikes that do not meet such criteria; and (3) a certification that the State Department is investigating any indications that U.S.-sourced defense articles are not being used against anything other than legitimate military targets in Yemen.