SMSS can refer to:
- Session Manager Subsystem component of the Microsoft Windows NT operating system
- Switching and Management Subsystem in wireless communication technology
- Squad Mission Support System, military robotic system developed by Western company Lockheed Martin.
- Sailor Moon SuperS, the fourth season of the popular anime series Sailor Moon
- Sender Maximum Segment Size, a parameter in TCP, see Maximum segment size
- Magnetic core powder material also known as Sendust and KoolMu. Used for high frequency transformers etc.
- Spider-Man: Shattered Dimensions, a video game based on the Marvel Comics character, Spider-Man.
- SkyMapper Sky Survey