The character is one of the pioneers of the genre and a major influence on Sherlock Holmes (who, in A Study in Scarlet, calls him "a miserable bungler"), laying the groundwork for the methodical, scientifically minded detective.

Father Bringer of Light, or "Old man Brings-to-light"), a title Lecoq himself will eventually inherit, Gaboriau also created an older mentor for Lecoq who, like Mycroft Holmes and Nero Wolfe, helps the hero solve particularly challenging puzzles while remaining largely inactive physically.

One inspiration for the character of Monsieur Lecoq came from a certain Eugène François Vidocq, a real life criminal who later became a policeman and eventually the first director of the Sûreté.

Another influence was a character named Monsieur Lecoq, who appeared in Les Habits Noirs, written by Paul Féval, père who had been Gaboriau's employer in 1862.

Honoré de Balzac introduced the notorious Vautrin, also inspired by Vidocq, in Le Père Goriot in 1834.