Who knew these notable celebrities pledged fraternities in college? "Who do you know here?" No, really. Do you know any of these celebs? They'll probably surprise you:

1. Luke Bryan - Sigma Chi (Georgia Southern University)

2. Ashton Kutcher- Delta Chi (University of Iowa)

3. Will Ferrell- Delta Tau Delta (University of South Carolina)

4. Brad Pitt- Sigma Chi (Mizzou)

5. Paul Ryan- Delta Tau Delta (Miami University in Ohio)

6. Eli Manning - Sigma Nu (Ole Miss)

7. David Letterman - Sigma Chi (Ball State University)

8. George W. Bush - Delta Kappa Epsilon (Yale University)

9. Jim Parsons- Pi Kappa Alpha (University of Houston)

10. Jimmy Buffett - Kappa Sigma (University of Southern Mississippi)

11. David Spade- Sigma Alpha Epsilon (Arizona State University)

12. Drew Carrey - Delta Tau Delta (Kent State University)

13. Tim McGraw- Pi Kappa Alpha (University of Louisiana at Monroe)

14. Steve Harvey- Omega Psi Phi (Kent State University)

15. Adam Sandler- Tau Epsilon Phi (New York University)

16. Matthew McConaughey- Delta Tau Delta (University of Texas at Austin)

17. Guy "Fieri"- Alpha Tau Omega (University of Nevada, Las Vegas)

18. Bob Parker- Sigma Nu (Drury University)

19. Woody Harrelson- Sigma Chi (Hanover College)

20. David Schwimmer- Delta Tau Delta (Northwestern University)