Boningen is a municipality in the district of Olten in the canton of Solothurn in Switzerland. Boningen is first mentioned in 1226 as in villa Bonnin…Boningen is a municipality in the district of Olten in the canton of Solothurn in Switzerland. Boningen is first mentioned in 1226 as in villa Bonningen. Boningen has an area, as of 2009, of 2.78 square kilometers. Of this area, 1.06 km² or 38.1% is used for agricultural purposes, while 0.77 km² or 27.7% is forested. Of the rest of the land, 0.71 km² or 25.5% is settled, 0.26 km² or 9.4% is either rivers or lakes and 0.01 km² or 0.4% is unproductive land.