The 1919 North Londonderry by-election was held on 4 March 1919. The by-election was held due to the resignation of the incumbent Irish Unionist MP, Hugh Anderson. It was won by the Irish Unionist candidate Hugh T. Barrie.[1] Barrie's Sinn Féin opponent, Patrick McGilligan, would later become Irish Minister for External Affairs.
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Irish Unionist | Hugh T. Barrie | 9,933 | 69.6 | -3.1 | |
| Sinn Féin | Patrick McGilligan | 4,333 | 30.4 | +3.1 | |
| Majority | 5,600 | 39.2 | -6.2 | ||
| Turnout | 14,266 | ||||
| Irish Unionist hold | Swing | -3.1 | |||