Cerniaz is a former municipality in the district of Broye-Vully in the canton of Vaud in Switzerland. The municipalities of Cerniaz, Combremont-le-Grand, Combremont-le-Petit, Granges-près-Marnand, Marnand, Sassel, Seigneux and Villars-Bramard merged on 1 July 2011 into the new municipality of Valbroye. Cerniaz is first mentioned in 1444 as Sernia. Cerniaz has an area, , of . Of this area, or 76.7% is used for agricultural purposes, while or 21.1% is forested. Of the rest of the land, or 3.9% is settled (buildings or roads). Of the built up area, housing and buildings made up 2.2% and transportation infrastructure made up 1.7%. Out of the forested land, 19.4% of the total land area is heavily forested and 1.7% is covered with orchards or small clusters of trees. Of the agricultural land, 63.3% is used for growing crops and 11.7% is pastures, while 1.7% is used for orchards or vine crops. The municipality was part of the Payerne District until it was dissolved on 31 August 2006, and Cerniaz became part of the new district of Broye-Vully. The former municipality is located on a plateau above the Broye valley and near the border with the Canton of Fribourg. It consists of the village of Cerniaz and the hamlet of La Morettaz. The blazon of the municipal coat of arms is Gules, three trunks bendwise eradicated Argent. Cerniaz has a population () of 42, all Swiss citizens. Over the last 10 years (1999–2009 ) the population has changed at a rate of -36.4%. It has changed at a rate of -30.3% due to migration and at a rate of -6.1% due to births and deaths. Most of the population () speaks French (62 or 98.4%) with the rest speaking German. Of the population in the municipality 28 or about 44.4% were born in Cerniaz and lived there in 2000. There were 20 or 31.7% who were born in the same canton, while 14 or 22.2% were born somewhere else in Switzerland, and 1 or 1.6% were born outside of Switzerland. In there was 1 live birth to Swiss citizens. Ignoring immigration and emigration, the population of Swiss citizens increased by 1 while the foreign population remained the same.