Will a Nikon flash work on a canon camera?

Short answer: "Not recommended" Long answer: The center contact on a flash shoe transmits the signal for a flash to fire. This contact is in the same place on all cameras that use a flash shoe. If a flash has ONLY the center contact, then it may be used on any camera that will accept it. However, each camera manufacturer adds additional contacts onto their flashes for various additonal purposes. These contacts are different for each manufacturer. Mounting a Canon flash onto a Nikon camera may send potentially damaging electrical charges, through the additional contacts, between the two devices. These charges can potentially damage both the camera and the flash.