The1912Ilkeston by-election was aParliamentary by-election held on 1 July 1912.[1] The constituency returned oneMember of Parliament (MP) to theHouse of Commons of the United Kingdom, elected by thefirst past the post voting system.

Jack Seely had been Liberal MP for the seat ofIlkeston since the1910 Ilkeston by-election. In 1912, he was promoted to the Cabinet and appointedSecretary of State for War and required to seek re-election.[2]
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Liberal | J. E. B. Seely | 9,990 | 62.7 | +2.9 | |
| Conservative | William Marshall Freeman | 5,946 | 37.3 | −2.9 | |
| Majority | 4,044 | 25.4 | +5.8 | ||
| Turnout | 15,936 | 81.9 | −5.8 | ||
| Liberalhold | Swing | +2.9 | |||
Polling Day was set for 1 July 1912.
Despite the mid-term unpopularity of the Liberal Government, Seely was re-elected, albeit with a much reduced majority.
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Liberal | J. E. B. Seely | 9,049 | 53.6 | −9.1 | |
| Unionist | William Marshall Freeman | 7,838 | 46.4 | +9.1 | |
| Majority | 1,211 | 7.2 | −18.2 | ||
| Turnout | 16,887 | 81.7 | −0.2 | ||
| Liberalhold | Swing | -9.1 | |||
A General Election was due to take place by the end of 1915. By the autumn of 1914, the following candidates had been adopted to contest that election.
Due to the outbreak of war, the election never took place. When an election did finally take place after the war, Seely was again re-elected.
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Liberal | J. E. B. Seely | 9,660 | 54.8 | +1.2 | |
| Labour | George Oliver | 7,962 | 45.2 | New | |
| Majority | 1,698 | 9.6 | +2.4 | ||
| Turnout | 17,622 | 61.0 | −19.3 | ||
| Liberalhold | Swing | ||||
Seely was endorsed by the Coalition Government. The local Unionists felt obliged to support Seely, however at the following general election in 1922 Freeman was once more their candidate but he finished third.