| Election Name: | 1891 Boston mayoral election |
| Type: | Presidential |
| Ongoing: | no |
| Previous Election: | 1890 Boston mayoral election |
| Previous Year: | 1890 |
| Election Date: | December 15, 1891 |
| Next Election: | 1892 Boston mayoral election |
| Next Year: | 1892 |
| Image1: | Nathan Matthews Jr. 5210004 015 030 (3x4a).jpg |
| Candidate1: | Nathan Matthews Jr. |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 34,708 |
| Percentage1: | 63.09% |
| Candidate2: | Horace G. Allen |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 19,532 |
| Percentage2: | 35.50% |
| Mayor | |
| Before Election: | Nathan Matthews Jr. |
| Before Party: | Democratic Party (United States) |
| After Election: | Nathan Matthews Jr. |
| After Party: | Democratic Party (United States) |
The Boston mayoral election of 1891 saw the reelection of Nathan Matthews Jr.