The military forces of the Vulcan High Command maintained a rank structure roughly equivalent to that of the Starfleet. (ENT: "Broken Bow")
Fleet commander[]
Fleet commanders reported directly to the High Command. They oversaw and commanded fleet engagements. (ENT: "Kir'Shara")
Captain[]
Captain was the rank commonly held by Vulcan starshipcommanders and other senior officers. (ENT: "Breaking the Ice", "Stigma") In the 1950s, Vulcan ship captains wore an angular-swirl insignia mirrored on the left and right collar, and additional dark striping from other officers on their uniform. (ENT: "Carbon Creek")
By 2151, Vulcan captains wore a single rank pin on their left collar. (ENT: "Breaking the Ice")
- Captain Oratt
- Captain Sokel
- Captain Sopek
- Captain Tavek
- Captain Tellus
- Captain Tok
- Captain Vanik
- Captain Voris
Sub-commander[]

Sub-commander insignia (2151)
Sub-commander was a rank subordinate to a Vulcan captain. In dealing with Starfleet, a sub-commander was considered above the rank of commander and below the rank of captain. (ENT: "Broken Bow")
Major[]

Major Talok (2154)
Major was a rank held by senior Vulcan field agents. (ENT: "Kir'Shara")
- Major Talok
Subaltern[]
Subaltern was a rank that existed sometime before 2375. (VOY: "Infinite Regress")
- Subaltern Lorot
Sublieutenant[]

A sublieutenant (2154)
Sublieutenants were junior officers of the High Command. A sublieutenant manned a security post outside AdministratorV'Las' office. (ENT: "Kir'Shara")
Background information[]
The Vulcan rank system seems to have been similar to Romulan ranks, including the use of sub-commander and sublieutenant.
The ranks of commander and lieutenant have never been referenced on-screen.