Semsales has a population () of . , 10.4% of the population are resident foreign nationals. Over the last 10 years (2000–2010) the population has changed at a rate of 13%. Migration accounted for 9.8%, while births and deaths accounted for 1.3%. Most of the population () speaks
French (956 or 93.8%) as their first language,
German is the second most common (29 or 2.8%) and
Portuguese is the third (9 or 0.9%). There are 7 people who speak
Italian. Of the population in the municipality, 457 or about 44.8% were born in Semsales and lived there in 2000. There were 260 or 25.5% who were born in the same canton, while 171 or 16.8% were born somewhere else in Switzerland, and 80 or 7.9% were born outside of Switzerland. , there were 407 private households in the municipality, and an average of 2.4 persons per household. , the construction rate of new housing units was 12.3 new units per 1000 residents. Colors= id:lightgrey value:gray(0.9) id:darkgrey value:gray(0.8) ImageSize = width:960 height:210 PlotArea = height:150 left:100 bottom:50 right:100 AlignBars = justify DateFormat = x.y Period = from:0 till:1100 TimeAxis = orientation:vertical AlignBars = justify ScaleMajor = gridcolor:darkgrey increment:200 start:0 ScaleMinor = gridcolor:lightgrey increment:40 start:0 PlotData= color:yellowgreen width:40 mark:(line,white) align:center bar:1850 from:start till:754 text:"754" bar:1860 from:start till:876 text:"876" bar:1870 from:start till:921 text:"921" bar:1880 from:start till:878 text:"878" bar:1888 from:start till:888 text:"888" bar:1900 from:start till:981 text:"981" bar:1910 from:start till:1001 text:"1,001" bar:1920 from:start till:1030 text:"1,030" bar:1930 from:start till:931 text:"931" bar:1941 from:start till:917 text:"917" bar:1950 from:start till:915 text:"915" bar:1960 from:start till:824 text:"824" bar:1970 from:start till:829 text:"829" bar:1980 from:start till:866 text:"866" bar:1990 from:start till:951 text:"951" bar:2000 from:start till:1019 text:"1,019" ==Politics==