His father, François Johannot (c. 1760–1838), owned a silk factory in Germany, where the family had fled after the revocation of the Edict of Nantes.
Tony learnt engraving from his brothers and helped Alfred produce illustrations of books by James Fenimore Cooper and Walter Scott.
His historical paintings were exhibited at the Paris Salon for the first time in 1831.
He became an illustrator much prized for his elegance, his diversity, and the lively character of his drawings, which were converted to engravings either by himself or by such artists as Jacques Adrien Lavieille, Émile Montigneul, and Alfred Revel.
He was praised by Théophile Gautier: Johannot died in Paris on 4 August 1852.