A Flagship is a ship that commands operations in a fleet. It can be any ship, as long as it is the ship commanding a fleet.
Speculation
Though it is speculated that Battlecruisers and Carriers are usually the flagships of a fleet or smaller unit structure.
Known Flagships
Covenant
- Seeker of Truth:
- Ascendant Justice: Unknown (possibly Reverence-class Cruiser)
- Sublime Transcendence: Supercarrier
- Incorruptible: Reverence-class Cruiser
UNSC
Although there has been no specific name of any ship mentioned as a flagship, there are likely one in every UNSC fleet.