Troistorrents (French pronunciation: [tʁwatɔʁɑ̃]; Arpitan: Trètorrent) is a municipality in the district of Monthey in the canton of Valais in Switzerland.

Troistorrents has an area, as of 2009[update], of 37 square kilometers (14 sq mi).

Rather it descends from the Latin "trans torrentium" which means "on the other side of the torrent".

The blazon of the municipal coat of arms is In azure with three Fir trees Vert stemmed proper, planted on three mountains of the same between which flow two mountain streams in pale Argent which fall into a third stream in fess; the mountain in the middle charged with a woman sitting, clothed Gules and holding on her knees her child dressed Argent and throwing grain Or.

[7] Most of the population (as of 2000[update]) speaks French (3,381 or 94.8%) as their first language, German is the second most common (90 or 2.5%) and English is the third (23 or 0.6%).

[7] The historical population is given in the following chart:[11] In the 2007 federal election the most popular party was the CVP which received 36.37% of the vote.

[13] In the 2007 Swiss Council of States election a total of 1,437 votes were cast, of which 106 or about 7.4% were invalid.

[7] There were 1,713 residents of the municipality who were employed in some capacity, of which females made up 38.6% of the workforce.

The number of jobs in the primary sector was 36, of which 31 were in agriculture and 6 were in forestry or lumber production.

In the tertiary sector; 94 or 22.8% were in wholesale or retail sales or the repair of motor vehicles, 34 or 8.3% were in the movement and storage of goods, 73 or 17.7% were in a hotel or restaurant, 1 was in the information industry, 15 or 3.6% were the insurance or financial industry, 11 or 2.7% were technical professionals or scientists, 55 or 13.3% were in education and 52 or 12.6% were in health care.

[7] From the 2000 census[update], 2,827 or 79.3% were Roman Catholic, while 312 or 8.7% belonged to the Swiss Reformed Church.

The library has (as of 2008[update]) 11,263 books or other media, and loaned out 12,540 items in the same year.

It was open a total of 320 days with average of 8 hours per week during that year.