Von Kempelen was born in Pressburg, today's Bratislava (Slovakia), part of the Kingdom of Hungary within the Habsburg Empire, the last child of Engelbert Kempelen (1680–1761), and Anna Theresa Spindler. Contrary to some reports, he did not hold the title of "Ritter" or "Baron." This misconception may stem from historical confusion with one of his older brothers, Johannes Nepomuk Joseph, who attained the rank of general within the Habsburg Empire, and who was granted the title "Kempelen von Pázmánd" after purchasing a former Jesuit estate in Pázmánd, a village south of Budapest.