The 2011 French Socialist Party presidential primary was the first open primary (primaires citoyennes) of the French Socialist Party and Radical Party of the Left for selecting their candidate for the 2012 presidential election. The filing deadline for primary nomination papers was fixed at 13 July 2011 and six candidates competed in the first round of the vote. On election day, 9 October 2011, no candidate won 50 percent of the vote, and the two candidates with the most votes contested a runoff election on 16 October 2011: François Hollande won the primary, defeating Martine Aubry.