No, we don't mean his personal toilet which is probably made of solid diamond with $100 bills for toilet paper.
They aim to improve sanitation and health worldwide.
The California Institute of Technology won first place and the $100,000 award for a solar-powered toilet that generates hydrogen and electricity.
The UK's Loughborough University won the $60,000 second place prize for a toilet that makes biological charcoal, minerals and clean water. Gross.
Third place and $40,000 went to a toilet that sanitizes waste and recovers resources and clean water. Also gross.
Bill Gates said:
"Innovative solutions change people's lives for the better. If we apply creative thinking to everyday challenges, such as dealing with human waste, we can fix some of the world's toughest problems."
The foundation also announced they'll be spending an additional $3.4 million on more grants for toilet innovations.
Though with 1.5 million children dying each year from diarrheal diseases, it's definitely an important area of research.
Congrats to all the winning toilet inventors!
[Image via Daniel Deme/WENN.]