This chapter begins with an examination of why people watch aggression and violence in sport and find it enjoyable and entertaining. This examination will compare four very different kinds of violent ‘sports’. These have been chosen because they represent ‘sport’ in the broadest sense of the term, they involve either real or fake violence, and they have or have had a high profile in terms of providing entertainment for very large numbers of spectators. In trying to explain why people enjoy these sports, concepts from reversal theory, including cognitive synergies, protective frames and parapathic emotions, will be included in the discussion. The chapter will go on to discuss broader aspects of a current academic debate on the possible effects of viewing media violence in general, and will then focus more specifically on the possible effects of viewing violence in sports. The sports chosen for discussion in the early part of this chapter are K-1, or ultimate fighting as it is sometimes known, professional wrestling, the manufactured-fortelevision ‘sport’ The American Gladiators, and violent sports depicted in science fiction sports films such as Rollerball and The Running Man.