Fontenais is a municipality in the district of Porrentruy in the canton of Jura in Switzerland. On 1 January 2013 the former municipality of Bressaucourt merged into the municipality of Fontenais. Fontenais is first mentioned in 1148 as Fonteneis. Fontenais has an area of . Of this area, or 48.7% is used for agricultural purposes, while or 43.5% is forested. Of the rest of the land, or 7.4% is settled (buildings or roads) and or 0.4% is unproductive land. Of the built up area, housing and buildings made up 4.9% and transportation infrastructure made up 1.6%. Out of the forested land, 41.8% of the total land area is heavily forested and 1.6% is covered with orchards or small clusters of trees. Of the agricultural land, 27.5% is used for growing crops and 19.0% is pastures, while 1.1% is used for orchards or vine crops and 1.1% is used for alpine pastures. The municipality is located in the Porrentruy district, south of the city of Porrentruy. It stretches across a small valley to the slopes of the surrounding mountains, where the main village developed. It consists of the village of Fontenais and the hamlet of Villars-sur-Fontenais as well as scattered farm houses. Somewhere on the Le Chételat hill, the remains of an 11th-century castle are supposedly buried. The blazon of the municipal coat of arms is Azure, a Fountain Argent, and on a Chief Or two Mullets [of Six] Gules. The fountain (fontaine) is an example of canting. Fontenais has a population () of . , 6.5% of the population are resident foreign nationals. Over the last 10 years (2000–2010) the population has changed at a rate of -1.7%. Migration accounted for -2.4%, while births and deaths accounted for 0.6%. Most of the population () speaks French (1,187 or 95.0%) as their first language, German is the second most common (35 or 2.8%) and Italian is the third (12 or 1.0%). the population was 48.0% male and 52.0% female. The population was made up of 550 Swiss men (44.2% of the population) and 47 (3.8%) non-Swiss men. There were 604 Swiss women (48.6%) and 43 (3.