The Real McCoy is a phrase used throughout much of the English-speaking world to mean "the real thing" or "the genuine article." See The Real McCoy was also a film starring Kim Basinger.

The origin of the phrase "The Real McCoy" is not generally agreed on. Some of the candidates are:

• Canadian inventor Elijah McCoy, who invented a machine to lubricate the moving parts of a railway locomotive
• A famous cattle baron of that name
• A Prohibition-era rum-runner named Bill McCoy
• The real Macao, pure heroin imported from the Far East
• The American boxer Norman Selby, known as Kid McCoy

In 1856, "the real MacKay" was a slogan for a Scotch whiskey, and may have been the original source.