Lieutenant commander is a military rank used in Federation Starfleet, superior to lieutenant and subordinate to commander. A lieutenant commander may be a senior officer in a department on a large vessel or starbase, or may be commanding officer or first officer of a smaller vessel.
A lieutenant commander is normally addressed as commander except in ceremonial contexts or printed orders.
The rank is equivalent to the Marines rank of major, wing colonel in the Federation Starfighter Corps (Star Trek: Remington), the Cardassian rank of glinn (excepting the Star Trek: Sigils and Unions continuity, where glinn is often equated with the rank of commander), and the Romulan rank of centurion.
The term comes from the navies of the 20th century. The USN abbreviation was LCDR.
Unlike other ranks such as lieutenant colonel or lieutenant general, a lieutenant commander is not a lesser version of commander, but rather is a more senior grade of lieutenant (other navies, such as those used in Germany and Russia, use the term 'captain lieutenant'). The rank was originally created because some lieutenants were being given command of smaller vessels in the United States Navy (where these officers were called 'lieutenant commanding' or 'lieutenant commandant') and the British Royal Navy (there referred to as 'lieutenant in command' or 'lieutenant and commander'); the US Navy adopted the resulting new rank of lieutenant commander in 1862, and the Royal Navy followed suit in 1914.
|22nd century||2230s||AR 2250s||2250s||2265-2270s||Early 2270s|
|File:Earth Starfleet - LCDR (Command).png||File:2230s - LCDR (Command).png||File:2250s - Officer (Command).png||File:2265 - LCDR (Command).png|
|File:2366 - LCDR (Command).png||File:2373 - LCDR (Command).png||File:2380s - LCDR (Command).png|
|File:2366 - LCDR Alternate (Command).png|
|File:2390s - LCDR (Command).png||File:2800 - LCDR (Command).png|
|Klingon navy|| Starfleet|
|File:2373 - LCDR (SFC).png|
Starfleet lieutenant commanders
|Enlisted ranks||Etc||Officer ranks||Flag ranks|
|Klingon Defense Force|
(Ground forces & navy)
|Bekk||Cpl||Sgt||MSgt||SgtMaj||2nd Lt||1st Lt||Capt|