John S. O'Connor (27 December 1896 – 2 November 1967) was an Irish revolutionary, solicitor and Fianna Fáil politician.

Alongside his brother Tommy, he took part in the Easter Rising, serving under the command of Ned Daly.

O'Connor was a section commander and was in charge of the barricades on May Lane beside the Jameson Distillery.

[1] Following the surrender of the rebels, O'Connor was imprisoned in Stafford Prison in England until his release in December 1916.

[3] O'Connor served as an election agent for three separate Fianna Fáil presidents of Ireland; Douglas Hyde, Seán T. O'Kelly and Éamon de Valera.