The magazine was founded in 1970 and aims to provide analysis and criticism of politics, culture, and the arts from those from both inside and outside the local mainstream. Fortnight is read by and contributed to by people from all over the spectrum. Gerry Adams is credited as saying "A month without Fortnight would be twice as long.
Previous contributors include politicians and journalists. For example David Trimble - ex-leader of the Ulster Unionists, and Newton Emerson - who spawned the popular satirical website the Portadown News.
Editors have included Tom Hadden, Andy Pollak, Leslie Van Slyke, Robin Wilson (later to found the Democratic Dialogue thinktank), John O'Farrell and Malachi O'Doherty. Literary editors have included the poets James Simmons and Medbh McGuckian. Cartoonist Martyn Turner has been a regular contributor since the magazine was founded, and also edited the magazine at one point.
Fortnight is currently supported by grants from the Arts Council of Northern Ireland.