The Shame actress auctioned off her custom Prada dress after wearing it on the red carpet to this year's Met Ball.
The dress sold for $2,950 (£1,860) when the auction closed on Saturday, May 19 with a total of 35 bidders. Proceeds from the sale will go to Oxfam America.
Last month, Mulligan married Mumford & Sons singer Marcus Mumford at a farm in Somerset before 100 guests that included Colin Firth and Jake Gyllenhaal.
She showed off her gold wedding band for the first time in public at the Met Ball.
Mulligan can be seen next in Baz Luhrmann's adaptation of The Great Gatsby, which will arrive in theatres on Christmas Day in the US and on December 26 in the UK.
Watch Carey Mulligan discussThe Great Gatsby with Digital Spy below: