The Old Maid and the Thief is a radio opera in one act by Italian-American composer Gian Carlo Menotti. The work uses an English language libretto by the composer which tells a twisted tale of morals and evil womanly power. Menotti writes in the libretto "The devil couldn't do what a woman can- Make a thief out of an honest man."

Commissioned by NBC, The Old Maid and the Thief was one of the earliest operas composed specifically for performance on the radio. Menotti wrote the libretto to The Old Maid and the Thief himself; initially in Italian but with the intention of having the work translated into English for its premiere. It was the first of several operas in the English language by the young composer who was just 28 years old at the time. He was inspired to write the story of the opera after visiting the family of his partner Samuel Barber. He found that what seemed to be a quaint, cute town actually covered up a plethora of secrets about people and places.

Upon the opera's premiere in 1939, the work was received with wide enthusiasm by American music critics. The success of the opera helped further establish Menotti's career in the United States.

Menotti later adapted the opera slightly so it could be performed on the stage; with the first theatrical production given in Philadelphia in 1941. The staged version of the work proved to be successful as well, and the opera is still occasionally mounted by professional companies. It is also a popular repertoire choice by university opera programs in the United States.