Les Bois has a population () of . , 9.7% of the population are resident foreign nationals. Over the last 10 years (2000–2010) the population has changed at a rate of 14.7%. Migration accounted for 12.2%, while births and deaths accounted for 3%. Most of the population () speaks
French (958 or 93.1%) as their first language,
German is the second most common (46 or 4.5%) and
Italian is the third (6 or 0.6%). Of the population in the municipality, 466 or about 45.3% were born in Les Bois and lived there in 2000. There were 128 or 12.4% who were born in the same canton, while 287 or 27.9% were born somewhere else in Switzerland, and 109 or 10.6% were born outside of Switzerland. , there were 373 private households in the municipality, and an average of 2.6 persons per household. , the construction rate of new housing units was 2.6 new units per 1000 residents. Colors= id:lightgrey value:gray(0.9) id:darkgrey value:gray(0.8) ImageSize = width:1020 height:210 PlotArea = height:150 left:100 bottom:50 right:100 AlignBars = justify DateFormat = x.y Period = from:0 till:1700 TimeAxis = orientation:vertical AlignBars = justify ScaleMajor = gridcolor:darkgrey increment:300 start:0 ScaleMinor = gridcolor:lightgrey increment:60 start:0 PlotData= color:yellowgreen width:40 mark:(line,white) align:center bar:1818 from:start till:1060 text:"1,060" bar:1850 from:start till:1339 text:"1,339" bar:1860 from:start till:1691 text:"1,691" bar:1870 from:start till:1697 text:"1,697" bar:1880 from:start till:1625 text:"1,625" bar:1888 from:start till:1575 text:"1,575" bar:1900 from:start till:1456 text:"1,456" bar:1910 from:start till:1323 text:"1,323" bar:1920 from:start till:1171 text:"1,171" bar:1930 from:start till:1153 text:"1,153" bar:1941 from:start till:1079 text:"1,079" bar:1950 from:start till:1064 text:"1,064" bar:1960 from:start till:1098 text:"1,098" bar:1970 from:start till:1110 text:"1,110" bar:1980 from:start till:917 text:"917" bar:1990 from:start till:974 text:"974" bar:2000 from:start till:1029 text:"1,029" ==Politics==