His father was Piero da Vinci, a respected Florentine notary. His mother was likely a young peasant woman named Catarina. Leonardo was raised by his father’s family, although due to his illegitimacy, he could never join the family profession and become a notary (bastards were barred from joining the notarys’ guild).
Which is just as well – the world is richer for Leonardo getting the chance to try everything he wished, advancing so many fields in the process.