"Ship classes" refers to the common practice of building multiple ships using a same or similar design. The design is then called a "class", and the class is often named after its 1st built or commissioned ship, or the initial design's code name. Ships built under the same class are then called "sister ships".

In Kancolle, several "classes" are instead referred to by their "type" (e.g. the Number 2-class is referred to as the Type D Kaiboukan).
Some informal classes are also sometimes used, such as the "Special Type Destroyers", or the ones listed bellow.

Ship Classes

Destroyer (DD)

Kamikaze-class

Mutsuki-class

Fubuki-class

Ayanami-class

Akatsuki-class

Hatsuharu-class

Shiratsuyu-class

Asashio-class

Kagerou-class

Yuugumo-class

Akizuki-class

Shimakaze-class

Matsu-class

Z1-class

Maestrale-class

Fletcher-class

John C. Butler-class

J-class

Mogador-class

Tashkent-class

Library Only Classes

The following is a list of cases where the class displayed in the game Library of a ship is different from the real ship's class.

None of those cases has any gameplay effect.
Those cases are purely cosmetic, often reflecting IRL concepts, or being fully made-up.

Library Only Classes	Ships
Kai Yamato-class	Yamato Kai Ni, Yamato Kai Ni Juu
Kai Ise-class	Ise Kai Ni, Hyuuga Kai Ni
Kai Kongou-class	Kongou Kai Ni C, Hiei Kai Ni C, Haruna Kai Ni B, Haruna Kai Ni C
Kai Akagi-class	Akagi Kai Ni, Akagi Kai Ni E
Kai Kaga-class	Kaga Kai Ni, Kaga Kai Ni E,
Kai Houshou-class	Houshou Kai Ni, Houshou Kai Ni Sen
Kai Ryuuhou-class	Ryuuhou Kai Ni, Ryuuhou Kai Ni E
Special Purpose Aircraft Carrier	Yawata Maru
Kai Agano-class	Noshiro Kai Ni, Yahagi Kai Ni, Yahagi Kai Ni B
Remodeled Kuma-class	Kuma Kai Ni, Kuma Kai Ni D
Kai Shiratsuyu-class	Umikaze Kai Ni^[1], Yamakaze Kai Ni^[1], Yamakaze Kai Ni D^[1]
Remodeled Shiratsuyu-class	Shigure Kai San, Harusame Kai Ni
Kai Kagerou-class	Yukikaze Kai Ni
Remodeled Kagerou-class	Dan Yang, Amatsukaze Kai Ni
Kai Yuugumo-class	Kiyoshimo Kai Ni, Kiyoshimo Kai Ni D
Kai Fletcher-class	Fletcher Mk.II
Kai Ukuru-class	Inagi Kai Ni
LL01	Souya (AGL)
PL107	Souya (AGB)

↑ ^1.0 ^1.1 ^1.2 Have its class number changed too

Equipment Classes

Some equipment in the game are simply treated as "ship girl's gears" and not as naval vessels proper. They are:

Daihatsu-class landing craft (and derivatives),
Toku Daihatsu-class landing craft (and derivatives),
Soukoutei-class armored boat,
Minisub Type A Kō-hyōteki-class midget submarine,
Minisub Type C Kō-hyōteki-class midget submarine,
Minisub Type D Kō-hyōteki-class midget submarine (Kouryuu).

Ship Class

Ship Classes

Kasuga Maru-class (Nitta Maru-class)

Perth-class (Amphion-class)