The average serve speed for a professional tennis player is 148 mph. But many players are capable of serving a lot faster. Here's the fastest servers in the ATP tour. 1. John Isner (USA): 157.2 mph 2. Milos Raonic (CAN): 155.3 mph 3. Andy Roddick (USA): 155 mph 4. Roger Federer (SUI): 143 mph 5. Andy Murray (UK): 141 mph 6. Novak Djokovic (SER): 136 mph 7. Rafael Nadal (SPA): 135 mph
