QI host Sandi Toksvig is paid 40% of the amount the panel show's former host Stephen Fry used to earn, she has told the Women's Equality Party conference.
Her fellow WEP co-founder Catherine Mayer tweeted that there was a "huge gasp" in the party conference room as Toksvig responded to a question on pay.
Toksvig, 60, took over from Fry in October 2016, who had hosted since 2003. She has filmed three series.
Producers Fremantle Media have made no comment on the difference.
The company makes the show, which runs on the BBC, and is set to return on Monday.
Answering a question about pay at the party conference, she said she had never wanted the equal pay argument to focus on her, she had a "nice living" and did "very well".
But she added: "I have recently discovered I get 40% of what Stephen used to get. And I get the same pay as (permanent panellist) Alan Davies, who is not the host.
"I temper this with the fact that I love the show and I'm the first woman to host such a show."
Later, she added: "I love QI and the brilliant team who produce it. John Lloyd and the (production) team champion women on the show."
The Women's Equality Party (WEP) which she established with Ms Mayer campaigns for women to have the same rights and opportunities as men.
Toksvig said she made the comments at the party's conference in answer to a question she felt she had to respond to "because the issues with equal pay and the gender pay gap cut right across the media and all industries and all areas of life".
"Until now I had held back from talking about this because this is not about me.
"However, the lack of transparency around pay is a big part of the problem and I hope that being open, I can support women across the country whose work is undervalued."
Toksvig also co-presents the Great British Bake Off. The amount she is paid for either roles has not been released.
The BBC press office said: "QI is made by an independent production company who manage their own talent fees."
Stephen Fry has also yet to comment on his successor's statements.