Callback can mean:
- Callback (computer programming), executable code that is passed as a parameter to other code
- Callback (telecommunications), the telecommunications event that occurs when the originator of a call is immediately called back in a second call as a response
- Callback verification, a method for e-mail address verification used in SMTP
- Callback (comedy), a joke which refers to one previously told in a set of jokes including both
- Web callback, a technology that provides telephone callback for websites
- In theater, film, or other performing arts, a follow-up after an audition or a casting, in which directors can further audition candidates for a position or part