| Native Name: | Département du Tanaro |
| Common Name: | Tanaro |
| Subdivision: | department |
| Nation: | French First Republic |
| Year Start: | 1801 |
| Event Start: | Decree of 24 Fructidor, year X[1] |
| Date Start: | 11 September |
| Year End: | 1805 |
| Event End: | Disbanded |
| Date End: | 6 June |
| P1: | Subalpine Republic |
| Flag P1: | Flag of the Repubblic of Alba.svg |
| S1: | Marengo (department) |
| Flag S1: | Flag of France.svg |
| Image Map Caption: | Administrative map of the Italian portion of the French Empire following the partition of the department. |
| Capital: | Asti |
| Political Subdiv: | 3 arrondissements |
| Stat Year1: | 1805 |
| Stat Pop1: | 310459 |
Tanaro (in French ta.na.ʁo/) was a short-lived department of the French Consulate and of the First French Empire in present-day Italy. It was named after the river Tanaro. It was formed in 1801, when the Subalpine Republic (formerly the mainland portion of the Kingdom of Sardinia) was intended to be annexed to France. Its capital was Asti, though Alessandria was the original intended capital.
The department was disbanded in 1805, when the French conquered the Ligurian Republic, and its territory was divided over the departments of Marengo, Montenotte and Stura.
The department was subdivided into the following arrondissements and cantons (situation in 1805):[2]
Its population in 1805 was 310,459.[2]