Thomas-Simon Gueullette (2 June 1683 – 2 December 1766) was a French lawyer, playwright, and scholar who also wrote fairy tales and works on the theatre itself.
A lawyer at the Châtelet de Paris, then substitute for the procureur du roi, Gueullette was a bibliophile who collected several placards and journals of his time.
His works on the Théâtre-Italien, which survive in manuscript, formed the basis for the Parfaict brothers in their Histoire de l'ancien Théâtre Italien.
Gueullette was the author of over 60 plays, many of which he put on at the Théâtre-Italien: La vie est un songe in 1717 (for which he was the translator), Arlequin-Pluton (1719); le Trésor supposé, en trois actes (s. d.); l’Horoscope accompli (1727), etc.
He also worked as an editor : Histoire du petit Jehan de Saintré (1724, 3 vol.