|Inner Sphere Military Ranks|
|For specific ranks see Military Ranks|
Depending on the faction, officers holding this rank typically command battalions or act as the executive officer of a larger formation. They also act as staff officers, handling logistics, intelligence, etc. for their units.
In the SLDF, majors were Regular Army battalion commanders and led their troops from the front. This led to them having more experience than their House Army counterparts. In the Star League Navy, a Major commanded destroyers or JumpShips transporting troops or cargo.
In the Second SLDF, a Naval officer at this rank was called Captain, and commanded a small WarShip, a transport JumpShip, or a wing of AeroSpace Fighters. This naval rank was a new feature of the second SLDF, and a radical departure from the first.
A Major's rank insignia was the same for both SLDF incarnations: A Captain's double green bars with a silver pip in between them.
|Rank||Insignia (First SLDF)||Insignia (Second SLDF)|
 Lyran Commonwealth and Lyran Alliance
 Draconis Combine Mustered Soldiery
|Rank||MechWarrior||AeroSpace Fighter||Infantry||Armor||Artillery|| Naval Crew
Draconis Combine Admiralty
 Armed Forces of the Federated Suns
In the AFFS a major typically commands a battalion, though elite tank and BattleMech companies were sometimes commanded by a major. Majors use epaulettes with one broad base across the bottom as their symbol of rank.
|Rank||MechWarrior||AeroSpace Fighter||Infantry||Armor||Naval Crew|| Technical
|Administrative||Medical||Legal|| Logistics/ |
 Capellan Confederation
Prior to Sun-Tzu Liao's ascension to the Celestial Throne, majors in the CCAF either commanded a 'Mech battalion or a regiment of three air squadrons. Staff officers with this rank often served in diplomatic, and logistic roles for the Senior Colonels that oversaw a Capellan Confederation commonality. The commanding officer of a Capellan Home Guard regiment was typically a major. As part of the Xin Sheng movement, Sun-Tzu Liao implemented a new system of ranks that used traditional Chinese names and brought the CCAF ranks in line with the militaries of other Successor States. Officers holding the rank of major under the older system became Zhong-shaos or Lieutenant Colonels. Sao-shao is the rank used for Major after the Xin Sheng movement was implemented. The sao-shao rank insignia is a brass bar with two silver pips.
 Free Worlds League
The FWLM is unique in the Inner Sphere because the militaries of the three largest provinces were integrated into one whole, but each province's military retained their existing rank structure until recently. This had meant that officers from the Marik Commonwealth could not have the rank of major, as those units used Force Commander but officers from the Duchies of Andurien and Oriente could hold the rank of major. Following the reforms of Captain-General Thomas Marik, the FWLM rank structure was streamlined and the rank of Force Commander formally replaced the rank of Major. Regardless of the rank's name, FWLM officers who held it would command battalions, or garrison units that were smaller than regimental size. Prior to the Succession Wars, officers with this rank would command marines aboard DropShips, JumpShips, and WarShips.
In the post Clan Invasion FWLM Navy, an officer with the rank of Force Commander is known as a Commander. Typically they serve as the executive officer of a FWLM Navy vessel. Sometimes a Commander will serve as the commanding officer of a JumpShip or DropShip while gaining the experience needed to be promoted to Captain.
| Force Commander
 The Clans
The Clans do not use the rank of Major. Instead a Clan warrior would have the rank of Star Captain or Star Colonel, depending on the situation. Some Clans however, notably Clan Hell's Horses, use the rank of Nova Captain to indicate a warrior who leads a Nova or Supernova.
 ComStar/Word of Blake
In the ComGuards and Word of Blake Militia, the equivalent rank would be Demi-Precentor or Adept, depending on the soldier's time of service. ComStar Adepts use a ComStar logo with a blue halo to show their rank, while Demi-Precentor's insignia use a red-yellow-blue halo. Word of Blake Adepts use a silver medallion, while Demi-Precentors use a gold medallion with silver branch of service letter. Insignia shows theta symbol, indicating JumpShip/WarShip crew. Other service branches replace theta with appropriate Greek letter.
|Rank||ComGuard Insignia||Word of Blake Militia Insignia|
 Free Rasalhague Republic
 Periphery Powers
 Magistracy of Canopus
A Magistracy Armed Forces Major is a battalion commander. Their rank insignia is a single gold diamond. In the Magistracy Navy, this officer rank is known as Comcapt, a combination of Commodore and Captain. Their rank insignia is a single gold diamond surrounded by a wreath.
 Taurian Defense Force
A battalion commander in the Taurian Defense Force is known as a Brigadier. In the TDF Navy, officers who hold this rank are known as an Air Master, Senior Grade or Air Master, SG. Their rank insignia is a single gold ring with a small "horn" on the left side.
 Marian Hegemony
This rank isn't used by the Marian Legions. With their focus on re-creating the Roman Empire, battalion commanders hold the rank of Legatus, Latin for deputy, officer, or legion commander. To show their rank, they wear a silver triangle with a black triangle in it, topped by a silver star.
 Outworlds Alliance
- ↑ The Star League, p. 103
- ↑ Field Manual: ComStar, p. 80
- ↑ The Star League, p. 113
- ↑ Field Manual: ComStar
- ↑ House Steiner (The Lyran Commonwealth), p. 117
- ↑ House Kurita (The Draconis Combine), p. 124, 129.
- ↑ House Davion (The Federated Suns), p. 128
- ↑ House Liao (The Capellan Confederation), p. 71
- ↑ House Marik (The Free Worlds League), p. 85
- ↑ House Marik (The Free Worlds League), p. 86
- ↑ Field Manual: Free Worlds League, p. 22
- ↑ Field Manual: ComStar, p. 66
- ↑ Field Manual: Periphery, p. 24
- ↑ Field Manual: Periphery, p. 53
- ↑ Field Manual: Periphery, p. 73
- ↑ Field Manual: Periphery, p. 88
- The Star League
- House Steiner (The Lyran Commonwealth)
- House Kurita (The Draconis Combine)
- House Davion (The Federated Suns)
- House Liao (The Capellan Confederation)
- House Marik (The Free Worlds League)
- Field Manual: ComStar
- Field Manual: Periphery
- Field Manual: Lyran Alliance
- Field Manual: Draconis Combine
- Field Manual: Free Worlds League
- Field Manual: Capellan Confederation
- Field Manual: Federated Suns