Krinau is a former municipality in the Wahlkreis (constituency) of Toggenburg in the canton of St. Gallen in Switzerland.

Of the rest of the land, 2.8% is settled (buildings or roads) and the remainder (0.6%) is non-productive (rivers or lakes).

It consists of the village of Krinau and the hamlets of Altschwil, Au, Dreischlatt, Gurtberg, Schuflenberg, Krinäuli, Niederberg, Kapf and Gruben.

The blazon of the municipal coat of arms is Or three Pine Trees Vert trunked Gules issuant from a Mount of the second.

[7] The age distribution, as of 2000[update], in Krinau is; 35 children or 12.6% of the population are between 0 and 9 years old and 46 teenagers or 16.5% are between 10 and 19.

[7] In the 2007 federal election the most popular party was the SVP which received 52.3% of the vote.

[3] Out of the total population in Krinau, as of 2000[update], the highest education level completed by 93 people (33.5% of the population) was Primary, while 83 (29.9%) have completed the Secondary level, 27 (9.7%) have attended a Tertiary school, and 9 (3.2%) are not in school.

[10] From the 2000 census[update], 88 or 31.7% are Roman Catholic, while 174 or 62.6% belonged to the Swiss Reformed Church.