Duties:

In charge of the security division of a starship or starbase

Post Holders:

- Malcolm Reed (Enterprise NX-01)
- Ellen Landry (USS Discovery)
- Ash Tyler (USS Discovery)
- Commander D. Nhan (USS Discovery)
- La'An Noonien-Singh (USS Enterprise)
- Pavel Chekov (USS Enterprise)
- Natasha Yar (USS Enterprise-D)
- Worf (USS Enterprise-D)
- Padraig Daniels (USS Enterprise-E)
- Odo (Deep Space Nine)
- Michael Eddington (Deep Space Nine & USS Defiant)
- Tuvok (USS Voyager)
- Shaxs (USS Cerritos)