Artist Marlene Dumas' melancholy piece, entitled Amy-Blue, is the first painted portrait of Winehouse to be acquired by the gallery, which houses images of icons such as Winston Churchill and Queen Elizabeth II.
The pale blue oil canvas, which depicts the singer wearing her trademark heavy eyeliner, has been given a wall to itself and is the first work visitors see when entering the contemporary galleries.
"The National Portrait Gallery is very pleased to acquire this important portrait of an influential singer and songwriter," said Sandy Nairne, Director of the National Portrait Gallery.
The portrait was bought for an undisclosed sum with support from the fundraising charity The Art Fund.
