The former US President, 78, grabbed his neck after the sound of shots rang, with images showing blood dripping from his right ear and down his cheek.
Rifle-wielding cops went into a panic, with the Secret Service seen jumping on the politician, who was visibly shocked.
After security staff rushed to protect him, the huddle stayed down for around a minute.
Trump later got up and raised his fist in defiance, appearing to clutch a red MAGA hat.
After getting on his feet, Trump was escorted off stage and into a vehicle, which drove him away from the scene.