Mels is a municipality in the Wahlkreis (constituency) of Sarganserland in the Seeztal, canton of St. Gallen, Switzerland.

Of the rest of the land, 2.6% is settled (buildings or roads) and the remainder (25.5%) is non-productive (rivers or lakes).

It consists of the village of Mels, the settlements of Heiligkreuz bei Mels, Plons, Ragnatsch, the hamlets of Butz, St. Martin, Mädris and Tils, the alpine settlement of Vermol as well as the Walser villages of Schwendi and Weisstannen.

Of the foreign population, (as of 2000[update]), 30 are from Germany, 228 are from Italy, 563 are from ex-Yugoslavia, 21 are from Austria, 90 are from Turkey, and 144 are from another country.

[8] The age distribution, as of 2000[update], in Mels is; 1,073 children or 13.7% of the population are between 0 and 9 years old and 1,137 teenagers or 14.5% are between 10 and 19.

[4] Out of the total population in Mels, as of 2000[update], the highest education level completed by 1,853 people (23.6% of the population) was Primary, while 2,780 (35.5%) have completed their secondary education, 586 (7.5%) have attended a Tertiary school, and 355 (4.5%) are not in school.

The A3 national motorway ends at Mels; the portion north toward St. Margrethen and the portion east toward Landquart, Chur, San Bernardino and ultimately Bellinzona are all part of the A13 national motorway.

Castels hill (which has been occupied from prehistory until the Middle Ages) and the early medieval church of St. Peter und Paul, are listed as Swiss heritage sites of national significance.

[12] From the 2000 census[update], 6,089 or 77.7% are Roman Catholic, while 625 or 8.0% belonged to the Swiss Reformed Church.