Major

Major was a military rank.

Human
Former British Army major Norman Baker was head of security at the Wenley Moor nuclear research facility. (TV: Doctor Who and the Silurians)

Barrington, (TV: The War Games) Daly (TV: Carnival of Monsters) and Popplewell (PROSE: Timewyrm: Exodus) were Majors of the British Army.

Walton (TV: Doctor Who and the Silurians), Alex Cosworth (TV: The Mind of Evil), Beresford (TV: The Seeds of Doom), Husak (TV: Battlefield) and Blake (TV: The Christmas Invasion) were UNIT Majors.

Branwell was a Major in command of the Henlow Downs missile site. (TV: The Invasion)

Rex Butcher was a Major and a writer on an alternate Earth. (PROSE: Atom Bomb Blues)

Ferdinand was the head of security at Mariah Learman's palace. (AUDIO: The Time of the Daleks)

Green was the Major in charge of security on the WOTAN project. (TV: The War Machines)

Alice Hunniford was an American Major. (AUDIO: Renaissance of the Daleks)

Alec Palmer was a Major turned Ghost-Hunter. (TV: Hide)

Shapp was an aide to the Marshal of Atrios. (TV: The Armageddon Factor)

Thessinger was a retired Major and a country landowner in England. (AUDIO: The First Sontarans)

Ian Warne was a Space Corps officer serving under General Nikolai Hermack. (TV: The Space Pirates)

Salateen was an officer in General Chellak's troop on Androzani Minor. (TV: The Caves of Androzani)

Sontarans
Varl, second-in-command to Group Marshal Stike, held the rank of major up to his death. (TV: The Two Doctors)

Stenx, leader for the Twelfth Sontaran Battle Fleet, held the rank of major up top his death. (PROSE: The Sontaran Games)

Skar was a Sontaran Major. (GAME: The Doctor and the Dalek)

Drak was a major in the 13th Sontaran Battlefleet.(COMIC: When Worlds Collide)

Tamasan was promoted to major sometime after the Battle of Tenacity. (AUDIO: The Lords of Terror)

Kreg was a major in the Ninth Sontaran Battle Brigade when he met Ianto Jones. (AUDIO: The Great Sontaran War)

Time Lords
Tamasan was a major in her fifth incarnation when she went to the Ogron Homeworld. (AUDIO: Planet of the Ogrons)

Others
Brogan, a Kaled captain, was promoted to major when relieving Colonel Nasgard, father to Davros and Yarvell. (AUDIO: Innocence)