Battleship

Battleships are the kings of the naval battlefield. These massive craft are protected by nigh-impenetrable defenses, carry enough firepower to obliterate a lesser ship, and usually have launch bays for attack craft as well.

The only weaknesses of a battleship are its expense and poor manuverability. However, when accompanied by cruisers and escorts to offset these disadvantages, a battleship becomes a nearly unstoppable addition to any fleet.

Imperial Navy

 * Apocalypse-class Battleship
 * Emperor-class Battleship
 * Oberon-class Battleship
 * Retribution-class Battleship

Space Marines

 * Battle Barge

Adeptus Mechanicus

 * Ark Mechanicus

Chaos Battleships

 * Desolator-class Battleship
 * Despoiler-class Battleship
 * Planet Killer

Eldar Battleships

 * Void Stalker

Ork Battleships
The Orks do not have any classes of battleship per se, but there are some individual ships that rival "true" battleships.
 * Ork "Battleships"

Necron Battleships

 * Cairn-class Tomb Ship

Tau

 * Gal'leath (Explorer)-class Battleship
 * Or'es El'leath (Custodian)-class Carrier

Allies

 * Demiurg Stronghold-class Commerce Vessel

Tyranid Battleships

 * Hive Ship