Lieutenant

Lieutenant was a junior rank in military, police and naval forces.

Human
Both Dan Galloway and Peter Hamilton were members of the Marine Space Corps expedition to Exxilon. (TV: Death to the Daleks)

Joe Sorba was a Space Corps Lieutenant onboard the V-41. (TV: The Space Pirates)

Atillo was one of the security officers on the rocket silo base on Malcassairo. (TV: Utopia)

Shears, (TV: Invasion of the Dinosaurs) Crane and Jeremy Carstairs (TV: The War Games) were all Lieutenants for the British Army.

Mercer was a crewmember of the Prison Station on which Davros was held prisoner. (TV: Resurrection of the Daleks)

Scott was the leader of a squad of troops ordered to some caves beneath the surface of the Earth in 2526. (TV: Earthshock)

Hugo Lang was a Lieutenant in the A Squadron of the Interplanetary Pursuit. (TV: The Twin Dilemma)

Lucke was a Lieutenant for the German Army. (TV: The War Games)

Stepashin was a Lieutenant for the Firebird. (TV: Cold War)

Koenig was an SS Lieutenant. (TV: Lost in Time)

Journey Blue was a Lieutenant in the Combined Galactic Resistance. (TV: Into the Dalek)

Alistair Gordon Lethbridge-Stewart was a Lieutenant before becoming Colonel and Brigadier. (PROSE: Transit)

Sam Bishop was a UNIT Lieutenant. (AUDIO: Earthfall)

Time Lord
Lieutenants were among the ranks of the Chancellery Guard. (PROSE: Blood Harvest)

Sontaran
Skree was a Lieutenant of the Tenth Sontaran Battle Fleet. (TV: The Sontaran Stratagem/The Poison Sky)

Vorn was a Lieutenant of the Sontaran party which boarded the ''Tiger Moth. (HOMEVID: Shakedown: Return of the Sontarans'')

Cybermen
A Cyber-Lieutenant was part of the leadership hierarchy of the Cybermen. The Lieutenant served as the assistant to the Cyber-Leader and possibly second-in-command of the Cyber-Force. (TV: Earthshock, Silver Nemesis)