As seen in What is Penny's last name in Big Bang Theory?
The main characters of Big Bang Theory (excluding Penny) are:
- Sheldon Lee Cooper
- Leonard Leakey Hofstadter
- Howard Joel Wolowitz
- Rajesh Ramayan Koothrappali
- Bernadette Maryanne Rostenkowski-Wolowitz
- Amy Farrah Fowler
As we don't know if Penny has a middle name or last we can't discount it, but Why do all the main characters have three names?