What does "speak of the devil" mean?

Said when someone appears at the exact moment you were talking about them. It signals coincidence and is usually used with a laugh or a smile.

"We were just talking about you - speak of the devil!"

The phrase is a friendly way to acknowledge that funny sense of timing when the person you mention suddenly turns up. It works best when the coincidence is real and noticeable to everyone in the room. You might say it as they walk through the door, or the second their name flashes up on your phone. Here are a few more natural examples:

"Speak of the devil, here she is now."

"We were just wondering where you'd got to, and speak of the devil, you appear!"

"I was about to call you about the meeting, and speak of the devil, you called me first."

"Speak of the devil and he shall appear" - a proverb warning that mentioning the devil would cause him to show up. The modern version drops most of this and keeps only the key phrase, now used humorously. The older wording carried a genuine superstitious weight, but today almost nobody uses the long form. Keeping just "speak of the devil" is what makes it sound light and modern.

Warm and slightly teasing. It's not an insult - comparing someone to the devil here is purely playful. The person being referred to usually laughs. Your voice matters here. Say it with a smile and a rising, cheerful tone, and it lands as a warm greeting. Say it flatly or coldly and it could sound sarcastic, so let your face and voice show that you're pleased to see them.

When someone walks in during a conversation about them, or texts/calls just as you mention them. Also works digitally: "I was literally just emailing you - speak of the devil!" It suits any moment where the timing is too perfect to ignore. It only makes sense when you were genuinely just talking about the person, so avoid using it as a plain hello when there was no earlier mention.

Casual. Works with friends and colleagues you know well.

In a casual setting with friends, it's completely natural and can be as cheeky as you like. In the workplace, it still works well with colleagues you're friendly with, and it can even break the ice in a light-hearted way when someone joins a meeting late. With a very senior person you don't know well, or in a formal client setting, you might soften it or skip it, since the "devil" comparison, though playful, assumes a relaxed relationship.

Learners sometimes say "talk of the devil" and worry they've got it wrong. In fact, "talk of the devil" is the common British version, while "speak of the devil" is more common in American English. Both are correct and both mean exactly the same thing, so use whichever feels natural to you. The mistake to avoid is using the phrase when there was no earlier conversation about the person, because then the coincidence it points to simply isn't there.

Picture yourself gossiping about a friend, and the moment their name leaves your mouth, they appear in the doorway as if you summoned them. Link the idea of "mentioning" someone to them "materialising." That image of accidentally calling a person into the room helps the phrase stick.

A very close cousin is "well, look who it is," which also greets someone with warm surprise, though it doesn't require that you were just talking about them. You might also hear "you must have ears burning," a playful way of telling someone you were discussing them. If you want a neutral, non-idiomatic option, you can simply say "what perfect timing." These give you a small toolkit of friendly reactions for those moments when life lines up a little too neatly.