A monk shoe is a style of shoe with no lacing, closed by a buckle and strap. It is also known as a monk strap, and has been called the "most advanced" dress shoe.
It is a moderately formal shoe: less formal than a full Oxford (American: Balmoral); but more so than an open Derby (American: Blücher). In between these, it is one of the main categories of men's shoes.
It often has a cap toe, is occasionally brogued, and is popular in suede.