The clameur de haro (French pronunciation: ​[klamœʁ də aʁo]) is an ancient legal injunction of restraint employed by a person who believes they are being wronged by another at that moment. It survives as a fully enforceable law to this day in the legal systems of Jersey and Guernsey, and is used, albeit infrequently, for matters affecting land.

The procedure is performed on one’s knees before at least two witnesses, in the presence of the wrong-doer, and in the location of the offence. The criant with his hand in the air must call out —

Haro! Haro! Haro! À l’aide, mon Prince, on me fait tort. (Hear me! Hear me! Hear me! Come to my aid, my Prince, for someone does me wrong.)