Signor Deluso is an opera buffa in one act composed by Thomas Pasatieri. The English-language libretto, written by the composer, is loosely based on Molière's 1660 comedy Sganarelle, ou Le Cocu imaginaire ("Sganarelle, or The Imaginary Cuckold"). It premiered on 27 July 1974 at the Madeira School auditorium in McLean, Virginia performed by the Wolf Trap Opera Company. It has been subsequently performed many times by various small opera companies in the United States and Europe. In a review of a 2008 revival in Washington, D.C., 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."