The 44-year-old received the Vanguard Award at the Glaad Media awards in Los Angeles for her advocacy of gay rights.
She was also recognised for her role as executive producer on The Fosters, a US drama series about a lesbian couple.
The American Idol judge paid tribute to her “loyal” GLBT fans for being “always on the floor and in my heart”.
“If I do anything that makes one child out there feel empowered… my dream has come true,” she told an audience at the Beverly Hilton Hotel.
The singer and actress received the Vanguard award, an accolade previously bestowed upon Cher, Liza Minnelli and Dame Elizabeth Taylor.
Other winners on Saturday included Canadian singing twins Tegan and Sara, NBC soap Days of Our Lives and The Fosters itself, which received the award for outstanding drama series.
Special awards were presented to veteran TV producer Norman Lear and transgender actress Laverne Cox, star of prison drama Orange is the New Black.
Glaad (Gay and Lesbian Alliance Against Defamation) will present a second awards event in New York on 3 May.