| Honorific Prefix: | Major-General |
| Henry MacKinnon | |
| Allegiance: |  United Kingdom |
| Rank: | Major-General |
| Branch: | British Army |
| Commands: | Talavera garrison Brigade, 3rd Division |
| Spouse: | Catherine Call |
| Relations: | Daniel Mackinnon (nephew) |
| Birth Date: | August 1773 |
| Death Date: | 19 January 1812 |
| Birth Place: | Longwood House, Winchester, England |
| Death Place: | Ciudad Rodrigo, Spain |
| Placeofburial: | Espeja, Spain |
| Serviceyears: | 1790–1812 |
| Battles: | |
| Awards: | Army Gold Medal with two clasps |
| Unit: | Coldstream Guards |
Major-General Henry MacKinnon (August 1773 – 19 January 1812), was a British soldier. He commanded the 45th Regiment of Foot, 74th (Highland) Regiment of Foot, and 88th Regiment of Foot in the Napoleonic Peninsular War under the Duke of Wellington. He was killed by the explosion of an enemy magazine during the Siege of Ciudad Rodrigo on 19 January 1812.
Prior to the Napoleonic wars, MacKinnon had a cordial acquaintance with Napoleon Bonaparte while the former's father resided in the French Province of Dauphiny when Napoleon was a frequent visitor to the region.[1]