Pigniu (German: Panix) is a former municipality in the district of Surselva in the canton of Graubünden in Switzerland.

On 7 October 1799, the Russian Army under command of Field Marshal Suvorov crossed the Pigniu pass.

The blazon of the municipal coat of arms is Gules St. Valentin clad Or and Argent holding his dexter in blessing and in sinister a crosier of the second standing above an ill Boy clad Sable.

Of the rest of the land, 0.4% is settled (buildings or roads) and the remainder (48.8%) is non-productive (rivers, glaciers or mountains).

[7] The age distribution, as of 2000[update], in Pigniu is; 7 children or 15.6% of the population are between 0 and 9 years old and 9 teenagers or 20.0% are between 10 and 19.

[5] The historical population is given in the following table:[2] Pigniu is a traditional farming community with no industry or commercial establishments.

The wettest month is August during which time Pigniu receives an average of 141 mm (5.6 in) of rain or snow.

The driest month of the year is October with an average of 90 mm (3.5 in) of precipitation over 16 days.