Let the Cat Out of the Bag

Last update:  May 27, 2026

Let the Cat Out of the Bag

“Let the cat out of the bag” means to reveal a secret or accidentally spoil a surprise. It’s one of those phrases that still feels vivid because it paints such a strange little picture in your mind.

The expression is generally traced back to the 15th or 16th century, with an early written example appearing around 1530. One popular origin story says it came from a marketplace trick, where someone expected to buy a piglet in a sack but found a cat instead when the bag was opened.

That unusual little image may be part of why the phrase has lasted for centuries. It’s memorable, weirdly humorous, and easy to use when a secret slips out before it should.

That’s the beauty of language, the phrases we use every day often carry a surprising history with them. They remind us that even ordinary words can hold onto a little story.

I also know someone who can’t keep a secret to save her life, her enthusiasm gets the better of her, and she’s always letting the cat out of the bag…and I love her quirkiness in this way.