Lieutenant junior grade (also called junior lieutenant, lieutenant j.g., or just j.g.) is a military rank used in Federation Starfleet from the 2280s through the 24th century, immediately superior to ensign and immediately subordinate to lieutenant. The corresponding rank in the marines is first lieutenant. Officers with rank lieutenant j.g. are addressed as 'lieutenant'.
The corresponding term in Commonwealth navies, including the Royal Navy of Britain, was sub-lieutenant. The RN has no equivalent of ensign, so sub-lieutenant was the most junior officer rank.
- The costume department for ENT did not have an insignia for it, so it never appeared on screen.
In the 2260s a single broken sleeve stripe was used as the insignia for junior lieutenants.
- This only appeared on screen once. Characters without sleeve stripes were variously addressed as 'crewman', 'ensign', or 'lieutenant'. Can we interpret the last as having recently been promoted to lieutenant j.g. but not got around to upgrading their uniform?
From the 2280s the lieutenant j.g. rank had a distinctive rank pin.
|Early 2380s||Mid 2380s||2390s|
|Klingon Navy||Lyran Starfleet|
|Enlisted ranks||Etc||Officer ranks||Flag ranks|
|Klingon Defense Force
(Ground forces & navy)
|Bekk||Cpl||Sgt||MSgt||SgtMaj||2nd Lt||1st Lt||Capt
- The rank system used in the 2270s did not have a LTJG rank.