Leggia 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.

Leggia is first mentioned in 1295 as de Legia.

Leggia had an area, as of 2006, of 9.2 km2 (3.6 sq mi). Of this area, 8.6% is used for agricultural purposes, while 63.9% is forested. Of the rest of the land, 2.7% is settled (buildings or roads) and the remainder (24.7%) is non-productive (rivers, glaciers or mountains).