Gloria Carter told an audience at the GLAAD Media Awards that it was the first time she’s spoken to anyone about who she really was.
The mother-of-four was presented with a special recognition gong for her contribution to his song Smile, released last year.
She said: “Smile became a reality because I shared with my son who I am.”
“My son cried and said: ‘It must have been horrible to live that way for so long.'”
“My life wasn’t horrible,” she added.
“I chose to protect my family from ignorance. I was happy but I was not free.”
Jay-Z has previously told how he cried with joy when his mother spoke to him about being a lesbian and of being in love with her female partner.
In the song on the rapper’s latest 4:44 album he says: “Mama had four kids, but she’s a lesbian/Had to pretend so long that she’s a thespian. Had to hide in the closet, so she medicate/Society shame and the pain was too much to take.”
He told US talk show host David Letterman: “For my mother to have to live as someone that she wasn’t and hide and like, protect her kids — and didn’t want to embarrass her kids… for all this time.
“For her to sit in front of me and tell me, ‘I think I love someone’. I mean, I really cried,” he told the David Letterman Netflix show.
He said he had long known she was gay, but the pair only had their first conversation about it last year.
Their chat came about while Jay-Z was making his latest album 4.44.
“This was the first time we had the conversation, and the first time I heard her say she loved her partner,” he said.