Santa Maria in Calanca is a municipality in the Moesa Region in the Swiss canton of Graubünden.

Of the rest of the land, 1.6% is settled (buildings or roads) and the remainder (19.6%) is non-productive (rivers, glaciers or mountains).

[8] The age distribution, as of 2000[update], in Santa Maria in Calanca is; 4 children or 3.6% of the population are between 0 and 9 years old.

[4] The historical population is given in the following table:[3] The Castello and the Church of S. Maria Assunta are listed as Swiss heritage sites of national significance.

Maria is a large pentagonal tower house with a two story vaulted ceiling.