- YST stands for Yoroiden Samurai Troopers (Japanese animation series created in the 1980s)
- YST stands for Yamaha Active Servo Technology (speakers)
- YST stands for Yahoo! Search Technology
- YST stands for Youth Sport Trust (UK)
- YST stands for Yukon Standard Time (GMT-0900)
- YST stands for Yellow Starthistle
- YST stands for You Sexy Thing
- YST stands for Yolk Sac Tumor
- YST stands for Youth Service Team
- YST stands for Youth Services of Tulsa
- YST stands for You Still There?
- YST stands for TIAFT Young Scientists
- YST stands for Yokosuka Saver Tiger (band; Japan)
- YST stands for Your Spanish Translation
YST