| Election Name: | 1921 Dudley by-election |
| Type: | presidential |
| Country: | United Kingdom |
| Previous Election: | Dudley (UK Parliament constituency)#Elections in the 1910s |
| Previous Year: | 1918 |
| Next Election: | Dudley (UK Parliament constituency)#Elections in the 1920s |
| Next Year: | 1922 |
| Election Date: | 3 March 1921 |
| Candidate1: | Wilson |
| Party1: | Labour Party (UK) |
| Popular Vote1: | 10,244 |
| Percentage1: | 50.7% |
| Candidate2: | Griffith-Boscawen |
| Party2: | Unionist Party (UK) |
| Popular Vote2: | 9,968 |
| Percentage2: | 49.3% |
| Map Size: | 250px |
| MP | |
| Posttitle: | Subsequent MP |
| Before Election: | Griffith-Boscawen |
| Before Party: | Unionist Party (UK) |
| After Election: | Lloyd |
| After Party: | Unionist Party (UK) |
The 1921 Dudley by-election was held on 3 March 1921. The by-election was held due to the appointment of the incumbent Coalition Conservative MP, Arthur Griffith-Boscawen, as Minister of Agriculture and Fisheries. It was won by the Labour candidate James Wilson. It was one of only eight ministerial by-elections in the UK to not be retained by the incumbent.