Julia Grenan (Sighle, Sheila, 2 July 1883 – 6 January 1972) was an Irish nationalist, republican, suffragette and socialist and member of Cumann na mBan, best known for being one of the three last women to leave the Headquarters during the Easter Rising of 1916.

They also ensured delivery of ammunition from the GPO to the College of Surgeons garrison, hiding the weapons under their clothes.

[6][7][8] O'Farrell was handed a Red Cross insignia and a white flag and asked to deliver the surrender to the British military.

While she heard the executions their wardress originally told the prisoners that the shots were from ongoing fighting.

[3] They collected funds during the Irish Civil War for the families of the anti-Treaty prisoners and continued to attend republican functions.

In the years after the Rising and wars Grenan worked for the Irish Hospital Sweepstakes office in Ballsbridge and also as a furrier in Dublin.

Similarly, their comrades in the 1916 Rising, Kathleen Lynn and Madeleine ffrench-Mullen, are also considered to be another "unstated" couple, as were Margaret Skinnider and Nora O'Keeffe,[10][11][12][13][14][15][16][17] all of whom were featured, along with Eva Gore-Booth and others, in a 2023 TG4 documentary about "the radical queer women at the very heart of the Irish Revolution": Croíthe Radacacha (Radical Hearts).