Staff officer

From Memory Alpha, the free Star Trek reference

A staff officer is a Starfleet officer that provides specialized support to line officers and all other persons in the organization. The staff officers of a specific vessel or institute together form a senior staff. These officers hold seniority positions in their departments, but are not necessarily senior officers. (DS9: "Crossfire") Members of the senior staff are sometimes referred to by the title "Department Head". (TNG: "Chain of Command, Part I")

[edit] Senior staff positions

The following positions can be considered as senior staff positions:

• commanding officer
• executive officer
• second officer
• chief communications officer
• chief science officer
• chief medical officer
• chief helmsman
• chief navigator
• flight controller
• chief engineer
• head counselor
• chief tactical officer
• security chief
• chief operations officer
• strategic operations officer
• intelligence officer
• chief of operations
• head stellar cartographer

Among the senior staff officers aboard Deep Space 9 in 2369 were Major Kira Nerys, Lieutenant Jadzia Dax and Doctor Julian Bashir. (DS9: "Move Along Home")