Lieutenant Simon "Ghost" Riley is a British special forces operator, and a prominent member of Task Force 141, known for his iconic skull-patterned balaclava, headset, and dark red sunglasses.

Ghost appears as a main character in Call of Duty: Modern Warfare 2, Modern Warfare 2: Ghost, Call of Duty: Online, Find Makarov: Operation Kingfish, Call of Duty: Heroes, and Call of Duty: Modern Warfare 2 Campaign Remastered. He also appears as a customization option in Call of Duty: Ghosts and Call of Duty: Infinite Warfare.