Signor Deluso is a hilarious opera buffain one act composed by Thomas Pasatieri. The English-language libretto, written by the composer, is loosely based on Molière’s 1660 comedy Sganarelle, or The Imaginary Cuckold. In a review of a 2008 revival, Anne Midgette described it as "an exuberant sendup of over-the-top comic opera plots, filled with effusive lovers leaping with alacrity to wrong conclusions in floods of extreme vocalism.
Gorgibus is forcing his daughter Célie to marry the wealthy Valère, but she is in love with Léon and he with her. However, a series of mistaken assumptions and quarrelling ensues after Célie faints in the town square and loses her locket with a portrait of Léon inside.