Sergey is a municipality in the district of Jura-Nord Vaudois in the canton of Vaud in Switzerland. Sergey is first mentioned in 1321 as Sergeys…Sergey is a municipality in the district of Jura-Nord Vaudois in the canton of Vaud in Switzerland. Sergey is first mentioned in 1321 as Sergeys. Sergey has an area, as of 2009, of 1.5 square kilometers. Of this area, 0.98 km² or 67.1% is used for agricultural purposes, while 0.28 km² or 19.2% is forested. Of the rest of the land, 0.21 km² or 14.4% is settled.