Lieutenant Commander (Lt. Commander) was a military rank attributed to Henry Clarke of the Naval Intelligence Division. (AUDIO: Criss-Cross, Quicksilver)
Newton Pallister, Vicki Pallister's father, was a Lieutenant Commander in the Merchant Space Marines. (PROSE: The Eleventh Tiger)
In a parallel universe, the android known as Data was a Lieutenant Commander of the Federation Starfleet who served aboard the USS Enterprise (NCC-1701-D). (COMIC: Assimilation²)