His father was Jacques Hubert Delaunay, a surveyor, and his mother was Catherine Choiselat, the daughter of a farmer. Charles was very close to his mother as a young child and remained so throughout his life.
Kanyang ama ay Jacques Hubert Delaunay, isang agrimensor, at ang kanyang ina ay Catherine Choiselat, ang mga anak na babae ng isang magsasaka. Charles ay masyadong malapit sa kanyang ina bilang isang batang bata at naiiwan kaya sa kabuuan ng kanyang buhay.