Marie-Étienne Nitot was born in Paris on 2 April 1750 to a family from Château-Thierry. He was apprenticed to Aubert, jeweller to Queen Marie-Antoinette, and set up on his own in Paris in 1780, the date Chaumet counts as its foundation. His aristocratic clients stayed with him until the Revolution of 1789, which he survived.

His house took off under the Consulate and Empire. He became jeweller to Napoleon (English Wikipedia's Chaumet article says in 1804; his own article says he was appointed in 1802) and, with his son François-Regnault Nitot (1779–1853), created jewellery to express the power of the new regime. He made the wedding jewels for Napoleon's marriages to Joséphine de Beauharnais and, later, to Archduchess Marie-Louise; designed and set the hilt of the coronation sword; and made the tiara that Napoleon presented to Pope Pius VII at the coronation of 1804. Father and son helped to reassemble the Crown Treasury, dispersed during the Revolution, and were exclusive suppliers of precious stones to the emperor.

Pieces attributed to Nitot include Joséphine's emerald parure, now owned by the Norwegian royal family; the Leuchtenberg sapphire parure, now in the Swedish royal jewel foundation; and the Cameo Tiara made for Joséphine. He died on 9 September 1809 and Napoleon appointed François-Regnault to succeed him. The Napoleon Diamond Necklace of 1811–1812 and the Marie-Louise Diadem of 1810, both now at the Smithsonian, are credited to "Nitot" in the sources but date from after Marie-Étienne's death, so they belong to the house under his son. François-Regnault, a royalist, withdrew after Napoleon's fall in 1815 and sold the business to his foreman, Jean-Baptiste Fossin.