Ethel Kennedy, the widow of the former attorney general, and Massachusetts Sen. John Kerry will award the prize to Frank Mugisha at a ceremony Thursday.
The 29-year-old activist has been fighting a bill in Uganda's parliament that would punish gay people with prison or death. It would also threaten jail time for family members, doctors or priests who don't report gays to authorities.
Mugisha blames U.S. evangelicals for promoting homophobia in Uganda.
In an interview with The Associated Press, Mugisha says the Kennedy award sends a message to Uganda and more than 70 countries that criminalize homosexuality that gay rights are human rights.