The Equalities Minister warned that if large firms do not close the gender pay gap voluntarily, then the Coalition will intervene to compel them to do so.
Ms Swinson welcomed the new momentum behind feminist campaigns, stressing how this was not about hating men but creating an equal society in modern Britain.
She told Elle magazine, which is running a "Make Them Pay" campaign to encourage women to ask their male colleagues about their salaries: "Sometimes there's something very British in our culture where we don't talk about money, and that holds women back.
"If they realised they were earning significantly less than male colleagues at a similar level, that might be the catalyst they need to ask for a pay rise."
Recognising there may be resistance from men to say how much they earned, the East Dunbartonshire MP added: "It's not like everyone's going to be comfortable about that, but trying to create a culture where people are open about these things can only help."
She added: "One of the things that is brilliant about the Elle campaign is encouraging people to open up about their pay. It's definitely something we should be encouraging women to feel confident about."
A clause in the Equalities Act could force firms to report gender pay gaps but the Coalition has not yet enacted it, preferring its voluntary Think, Act, Report scheme, encouraging firms to publish information.
"I would agree that while the pay gap is reducing a bit, it's not reducing enough, given that we're 40 years on from the initial legislation to say that men and women ought to be paid equally," said Ms Swinson.