Verdabbio is a former municipality in the district of Moesa in the Swiss canton of Graubünden. On 1 January 2017 the former municipalities of Leggia and Verdabbio merged into the municipality of Grono.

Verdabbio is first mentioned in 1203 as Vertabio.

Verdabbio had an area, as of 2006, of 13.1 km2 (5.1 sq mi). Of this area, 4.9% is used for agricultural purposes, while 62.1% is forested. Of the rest of the land, 1.1% is settled (buildings or roads) and the remainder (31.9%) is non-productive (rivers, glaciers or mountains).