YB is an abbreviation for:
- Ytterbium, a chemical element
- Young Buck, a rapper
- BSC Young Boys, a Bernese soccer club
- Yottabyte, a unit of information or computer storage
- Ypatingasis būrys
- Youngstown Belt Railroad
- Yoon Do Hyun Band, a South Korean rock band
- Yahoo! Buzz
- Yahoo! Briefcase
- Yahoo! Broadcast
- Yahoo! Search BOSS
- Yahoo bot