Ömer Halisdemir (February 20, 1974 – July 16, 2016) was a Turkish non-commissioned officer, who was killed on duty in the night of failed 2016 Turkish coup d'état attempt, immediately after he shot dead pro-coup general Semih Terzi and prevented the capture of the headquarters of the Special Forces Command in Ankara by the rebel forces. His actions are recognized as a major reason for the failure of the coup attempt.