The 1936 Greenock by-election was a by-election held on 26 November 1936 for the UK House of Commons constituency of Greenock in Renfrewshire, Scotland.
The seat had become vacant on 13 October 1936 when the Secretary of State for Scotland, Sir Godfrey Collins died at the age of 61. A National Liberal Member of Parliament (MP), he held the seat since the January 1910 general election.
The National Liberal candidate was V. E. Cornelius, who had not previously contested a parliamentary election.
His only opponent was the Labour Party candidate, 50-year-old Robert Gibson. Gibson had unsuccessfully contested one by-election and three general elections most recently at Dundee in 1935.
On a high turnout, the result was a victory for Gibson, who won the seat with a swing of nearly 8%. He held the seat until his resignation in 1941.
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Labour | Robert Gibson | 20,594 | 53.4 | +9.4 | |
| National Liberal | V. E. Cornelius | 17,990 | 46.6 | −6.1 | |
| Majority | 2,604 | 6.8 | N/A | ||
| Turnout | 38,584 | 83.3 | −1.1 | ||
| Labour gain from National Liberal | Swing | +7.85 | |||
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| National Liberal | Godfrey Collins | 20,299 | 52.7 | +1.6 | |
| Labour | T. Irwin | 16,945 | 44.0 | +13.3 | |
| SNP | J. L. Kinloch | 1,286 | 3.3 | New | |
| Majority | 3,354 | 8.7 | −15.7 | ||
| Turnout | 38,530 | 84.4 | +4.1 | ||
| National Liberal hold | Swing | −5.9 | |||