Party leader Natalie Bennett claimed the move would bring in an extra £2 billion a year for public services.
She said the Greens would like to see a "ten to one ratio between the top paid and lowest paid".
The top rate of tax is paid on incomes over £150,000-a-year and currently stands at 45p, after it was cut from 50p by the coalition.
Main pledges
Policy guide: Where the parties stand
Labour has said it would re-introduce the 50p top rate if it wins the general election on 7 May.
Ms Bennett told the BBC's Andrew Marr Show: "There's been an undue focus on the deficit and less thought and consideration on the kind of society we need to have.
"We're not collecting tax from multinational companies and wealthy individuals that could be paying for the essential public services, and we're seeing so many people in our society struggling."
She said the proposed 60p rate would apply to people earning over £150,000 and the Greens expected it to raise £2bn a year.
Ms Bennett said that "inequality in our society is a huge and rising problem" and her party wanted to see a "10 to one ratio between the top paid and lowest paid person in an organisation".
The Greens have also proposed a "wealth tax" which would be 2% a year levied on people with assets of more than £3m which, Ms Bennett claimed, could bring in £25bn a year "by the end of the Parliament".
Wealthy individuals would be expected to declare assets themselves. but the Green Party leader said research from the US showed that people will "declare fairly" if they think they are going to get caught otherwise.
Andrew Marr also asked Ms Bennett if a ban on the Grand National would be part of the Greens' animal welfare policies.
Ms Bennett failed to answer but said:  "I can give you an exclusive preview of our manifesto, which says we want a complete review of all horse and greyhound racing."
She argued that "there are clearly animal protection issues there which need to be addressed".
Asked whether she'd had "a flutter" on Saturday's race, she said:  "I confess I wasn't watching, didn't know anything about it."
The Green Party has announced it would put up the top rate of tax to 60p in the pound.