ESW can mean:
- Engineers for a Sustainable World, a national not-for-profit based in Pittsburgh, Pennsylvania.
- Empire State Wrestling, an independent wrestling promotion that has operated in Western New York State since 2002.
- Embedded software, computer software that plays an integral role in the electronics it is supplied with.
- Electroslag welding, a single pass welding process.
- Every Single Word, a YouTube channel and Tumblr blog dealing with POC representation in media.