Silence of the Lambs actress, 50, accepted the Cecil B. DeMille Award at Sunday's Golden Globes, where she delivered an emotional speech that left members of the audience in tears.
In her speech, Foster opened up to the crowd about her sexuality, her relationship with the media, and her mother.
"While I'm here being all confessional, I guess I just have just a sudden urge to say something that I've never really been able to air in public.
"[It's] a declaration that I'm a little nervous about – but maybe not quite as nervous as my publicist right now. I'm just going to put it out there – loud and proud."
She added after a pause: "I am single."
She continued: "This is not going to be a big coming out speech tonight because I already did my coming out about a thousand years ago back in the stone age – in those very quaint days when a fragile girl would open up to trusted friends and family and coworkers and then gradually proudly to everyone who knew her."
She also thanked Cydney Bernard, telling the audience she is 'one of the deepest loves of my life, my heroic co-parent, my ex-partner in love but righteous soul sister in life, my confessor, ski buddy, consigliere, most beloved BFF of 20 years'.
She added: "I am so proud of our modern family, our amazing sons, Charlie and Kit who are my reason to breathe and to evolve."
The actress also opened up about her mother, saying:
"I love you, I love you, I love you and I hope if I say this three times, it will magically and perfectly enter into your soul, fill you with grace and the joy of knowing that you did good in this life."