The 19-nation currency rose to $1.1088 from around $1.1027 before the announcement, and after dropping to $1.0963 in New York electronic trade Sunday after the country rejected creditors' austerity demands in a landmark weekend referendum.
Outspoken and flamboyant Varoufakis clashed with Greece's creditors and refused to bow to their demands for tough austerity.
But he announced that the was quitting on his blog and social media just hours after the successful "No" vote against more belt-tightening.
"Soon after the announcement of the referendum results, I was made aware of a certain preference by some Eurogroup participants, and assorted 'partners', for my... 'absence' from its meetings," Varoufakis wrote.
It was "an idea that the Prime Minister judged to be potentially helpful to him in reaching an agreement. For this reason I am leaving the Ministry of Finance today."