Bütschwil had a population (as of 2011) of 3,365. , about 15.7% of the population was made up of foreign nationals. Of the foreign population, (), 28 are from Germany, 83 are from Italy, 318 are from ex-Yugoslavia, 5 are from Austria, 165 are from Turkey, and 65 are from another country. Over the last 10 years the population has decreased at a rate of -7.2%. Most of the population () speaks German (88.2%), with Albanian being second most common ( 3.6%) and Serbo-Croatian being third ( 1.8%). Of the Swiss national languages (), 3,131 speak German, 5 people speak French, 62 people speak Italian, and 2 people speak Romansh.