Below are the top 20 most watched MMA bouts in US history; please bear in mind that these bouts are the most watched in US history, not world history:

1. EliteXC on CBS (5/31/2008): Kimbo Slice vs. James Thompson – 7.281 million viewers

2. UFC on Spike TV (10/10/2006): Tito Ortiz vs. Ken Shamrock – 6.524 million viewers

3. EliteXC on CBS (10/4/08): Seth Petruzelli vs. Kimbo Slice – 6.451 million viewers

4. EliteXC on CBS (5/31/2008): Robbie Lawler vs. Scott Smith – 5.867 million viewers

5. UFC on Spike TV (9/8/2007): Quinton Jackson vs. Dan Henderson – 5.811 million viewers

6. EliteXC on CBS (5/31/2008): Gina Carano vs. Kaitlin Young – 5.508 million viewers

7. UFC on Spike TV (9/8/2007): Michael Bisping vs. Matt Hamill – 5.475 million viewers

8. EliteXC on CBS (10/4/08): Jake Shields vs. Paul Daley – 5.338 million viewers

9. EliteXC on CBS (10/4/08): Gina Carano vs. Kelly Kobold – 5.171 million viewers

10. EliteXC on CBS (10/4/08): Andrei Arlovski vs. Roy Nelson – 5.154 million viewers

11. UFC on Spike TV (10/10/2006): Kendall Grove vs. Chris Price – 5.1 million viewers

12. UFC on Spike TV (9/8/2007): Cheick Kongo vs. Mirko Cro Cop Filipovic – 5.098 million viewers

13. UFC on Spike TV (9/8/2007): Marcus Davis vs. Paul Taylor – 5.023 million viewers

14. UFC on Spike TV (7/19/2008): Anderson Silva vs. James Irvin – 4.795 million viewers

15. EliteXC on CBS (5/31/2008): Joey Villasenor vs. Phil Baroni – 4.348 million viewers

16. UFC on Spike TV (10/10/2006): Jason MacDonald vs. Ed Herman – 4.297 millon viewers

17. UFC on Spike TV (9/8/2007): Houston Alexander vs. Alessio Sakara – 4.204 million viewers

18. UFC on Spike TV (10/10/2006): Matt Hamill vs. Seth Petruzelli – 4.007 million viewers

19. UFC on Spike TV (7/19/2008): Brandon Vera vs. Reese Andy – 3.847 million viewers

20. EliteXC on CBS (5/31/2008): Brett Rogers vs. Jon Murphy – 3.824 million viewers