A staff officer was any member of a group of officers, enlisted, and civilian personnel on a starship, starbase, or planetary base, who were responsible for the administrative, operational, and logistical support. Collectively, they were known as the senior staff or command crew. These officers held seniority positions in their departments, but were not necessarily senior officers. (DS9: "Crossfire")
Members of the senior staff presided over their department heads; some department heads were also members of the senior staff. (TNG: "Chain Of Command, Part I"; TOS: "Where No Man Has Gone Before"; Star Trek) At staff meetings it was protocol for the senior officer to speak for their departments. (VOY: "Parallax")
First Minister Shakaar Edon had but a single member for his senior staff: Sarish Rez, who titled himself as "the First Minister's adjutant." (DS9: "Crossfire")
Senior staff positions
The following positions could have been considered as senior staff positions:
- Commanding officer
- First officer (TNG: "Coming of Age", "The Loss"; DS9: "Move Along Home", "Crossfire", "Paradise Lost")
- Second officer
- Third officer
- Chief communications officer
- Chief science officer (DS9: "Move Along Home")
- Chief medical officer (Star Trek III: The Search for Spock; TNG: "When The Bough Breaks", "Coming of Age", "The Loss"; DS9: "Move Along Home")
- Chief tactical officer
- Chief helmsman
- Chief navigator
- Chief conn officer (VOY: "Thirty Days")
- Chief engineer (TNG: "The Loss"; VOY: "Parallax")
- Head counselor
- Chief of security (TNG: "Coming of Age", "The Loss")
- Chief of operations (TNG: "The Loss"; DS9: "Crossfire")
- Strategic operations officer
- Intelligence officer
- Head stellar cartographer