The winners were announced on Tuesday night's finale of the Fox show for which Cat Deeley serves as host.
Girard, 21, from West Palm Beach, Fla., and Wespi-Tschopp, 23, from Zurich, Switzerland, earned the most viewer votes and won the cash prize of $125,000 each.
"What I have imagined winning would feel like was like winning the lottery," Girard said. "I hoped for it every single day and when it actually happened I felt like my life was complete. Whatever happens afterwards doesn't matter because all my dreams have come true! And I want to take the time to thank all the fans for their support, because they don't realize how much they helped me get through this! And, of course, my family, too! I love you guys and thank you a bazillion times over!"
"Winning 'So You Think You Can Dance' gives me the most unbelievable and rewarding feeling," Wespi-Tschopp said. "It is a truly special ending to my journey, far beyond anything that I thought possible. It gives me a great sense of accomplishment that all the hard work that I've put in since starting ballet at 13 was completely worth it. I'd like to thank this show for giving me the opportunity of a lifetime, and to all my supporters who have made me believe in my talents, and most importantly, my parents, who have always been there for me and sacrificed so much for me to pursue my dream!"