Lieutenant

In the Earth Starfleet, the rank of Lieutenant was directly between Ensign and Commander. The Federation Starfleet uses additional grades in this transition, so the rank of Lieutenant stands betweenLieutenant Junior Grade, Lieutenant Commander. This is identical to the system used by many older Earth agencies. Starfleet lieutenants are expected to be effective small-section leaders and technical experts, developing their leadership skills in preparation for promotion to the commander tier.

Lieutenants Ranks
List of Lieutenants