A third officer is an officer of a starship that is fourth in line of command of the vessel after the captain, first officer, and second officer. In Starfleet, the position is generally filled by a lieutenant commander or lieutenant. The security chief, tactical officer, or chief engineer is sometimes given this position. As with the position of second officer, the third officer's main duties are as a department head.
Known third officers
|Enlisted personnel||Commissioned officers||Generals and flag officers|
|ENS||LT JG||LT||LT CMDR||CMDR||CAPT||FCAPT||CDORE||RADM||VADM||ADM||FADM|
|2nd LT||1st LT||CAPT||MAJ||LT COL||COL||BRIG||MAJ GEN||LT GEN||GEN||MARSHAL|
|Positions:||Crewman • Technician • Chief||YMN||TAC • SO • 3rd • 2nd • 1st • CO • DD||Portmaster • Chief of Staff • CinC|
|Services:|| Andorian • Bajoran • Cardassian • Jem'Hadar • Klingon • Romulan • SS • Terran Empire Starfleet • Terran Empire MACO •|
United Earth MACO • United Earth/Federation Starfleet • United States • Vulcan