| 21st Michigan Infantry Regiment | |
|---|---|
 Michigan state flag | |
| Active | September 9, 1862, to June 8, 1865 |
| Country |  United States |
| Allegiance | Union |
| Branch | Infantry |
| Engagements | Battle of Perryville Battle of Stones River Battle of Chickamauga Battle of Chattanooga March to the Sea Siege of Savannah Battle of Bentonville Battle of Averasborough |
The 21st Michigan Infantry Regiment was an infantry regiment that served in the Union Army during the American Civil War.