| Election Name: | 1919 Oxford University by-election |
| Type: | presidential |
| Country: | United Kingdom |
| Previous Election: | Oxford University (UK Parliament constituency)#Elections in the 1910s |
| Previous Year: | 1918 |
| Next Election: | Oxford University (UK Parliament constituency)#Elections in the 1920s |
| Next Year: | 1922 |
| Election Date: | 19–24 March 1919 |
| Candidate1: | Oman |
| Party1: | Unionist Party (UK) |
| Popular Vote1: | 2,613 |
| Percentage1: | 52.52% |
| Candidate2: | Murray |
| Party2: | Liberal Party (UK) |
| Popular Vote2: | 1,330 |
| Percentage2: | 26.73% |
| Candidate3: | Riley |
| Party3: | Independent politician |
| Popular Vote3: | 1,032 |
| Percentage3: | 20.74 |
| Map Size: | 250px |
| MP | |
| Posttitle: | Subsequent MP |
| Before Election: | Prothero |
| Before Party: | Unionist Party (UK) |
| After Election: | Oman |
| After Party: | Unionist Party (UK) |
The 1919 Oxford University by-election was held on 19–24 March 1919 after the incumbent Coalition Conservative MP, Rowland Prothero was created as the first Lord Ernle. It was retained by the Conservative candidate Prof. Charles Oman.