Lieutenant Commander may serve in positions such as section chiefs, responsible for the functioning of a department such as Engineering, Security, or Medical. A Lieutenant Commander may also serve as a commander of the bridge in the position of Second Officer to the Captain and First Officer.
- Strictly speaking, most if not all Union officers of a higher rank seen would have been Lieutenant Commanders. The following are those who are definitively seen as such.
- Bortus: The current Second Officer of the Exploratory-class USS Orville.
- Steve Newton: Was the Chief Engineer of the Orville before being assigned to help construct a new space station in early 2420.
- John LaMarr: The current Chief Engineer of the Orville.
- Claire Finn: The current Chief Medical Officer of the Orville, joined in September 2419.
- Murphy: Served aboard the USS Chanute; became eligible for a First Officer position after being promoted in 2419.