Broadcaster Clare Balding said her grandmother told her she was "disgusting" and the pair did not speak for months after it was revealed she was gay.
The presenter, who played a large part in the BBC's Olympics coverage, also said she will go to Russia to cover the 2014 Winter Olympics despite controversy over the country passing what are widely seen as anti-gay laws.
Clare, whose partner is former newsreader Alice Arnold, was outed in a newspaper around 10 years ago when they were pictured together at a film premiere.
Appearing on BBC Radio 4's Desert Island Discs, she said the experience had been "kind of weird".
Slare, whose parents were aware she was gay, said she had to tell her grandmother.
She told host Kirsty Young: " I said 'Grandma I need to talk to you' and she said 'Yes I should think you do'.
"I said 'Have you seen the paper?' and s he said 'Yes and I think it's disgusting'.
"I said 'What do you mean? The invasion of my privacy or my lifestyle choice' and she said 'Both' and I didn't talk to her for about six months after that which was pretty difficult."
Clare grew up in a horse training family and was an amateur flat jockey before joining the BBC where she regularly presented racing and has worked on five Olympic Games.
Asked if she could work at the 2014 games in Sochi with "a clear conscience", Clare said: "A bsolutely, because I think it's hugely important that I do go."
Asked if she should boycott the games, she said " it would make absolutely no difference at all to anyone in Russia would it?".
She added: "I mean I didn't do the Open golf at Muirfield last summer, I didn't make a big song and dance about it but I felt morally I couldn't go to an all-male club and sell this great golf event when I knew I wouldn't be allowed there on any day of the week.
"I will make a moral stand on things but in this instance the right thing to do is go".