A caller is someone who makes a phone call or visits someone's home. When you pick up the phone and dial a friend's number, you're the caller. When someone rings your doorbell, they're a caller at your door.

The word has special meanings in different contexts. At a square dance, the caller is the person who shouts out instructions, telling dancers which moves to do next: “Swing your partner!” or “Do-si-do!” Without the caller's clear voice guiding everyone through the steps, the dance would dissolve into confusion.

In games like bingo, the caller announces which numbers have been drawn. Players wait eagerly for the caller to shout “B-7!” or “O-63!” so they can mark their cards.

When you phone someone, you might hear “Caller, are you there?” if the connection is bad, or see “Unknown Caller” flash across the screen when someone's number doesn't show up. The person receiving your call is sometimes called the callee, though that word is much less common.