Her win in east Belfast, unseating the First Minister Peter Robinson, was the biggest shock in the general election in Northern Ireland, if not in the whole of the UK.
But who is Naomi Long? BBC News Online profiles the new MP for East Belfast.
Born in 1971, Naomi Long grew up in the heart of her constituency, attending Mersey Primary School and Bloomfield Collegiate School.
She then earned a distinction in a Masters in Civil Engineering at Queen's University, Belfast.
She first took political office in 2001 when she was elected to Belfast City Council for the Victoria ward.
Her rise was relatively meteoric - she became an Assembly member for East Belfast in the 2003 election and within three years became deputy leader of the party.
Despite her higher profile, she maintained her interest in local government and became only the second female Lord Mayor of Belfast in 2009.
Her husband Michael is also a politician, serving on Castlereagh Borough Council.
Despite her busy political career, Ms Long also finds time for other activities. She serves on the committee of Bloomfield Presbyterian Church and is a senior guider with the Girl Guides.