Carbine

A carbine is a shorter, often lighter, version of a full-sized rifle. When applied to pistols, it typically refers to a conversion kit applied to the pistol to offer some of the advantages of a rifle in a more compact form.

United Nations Space Command

 * M6J/C Carbine - The UNSC carbine variant of the M6 series of firearms, used by the UNSC Army.
 * MA5K Carbine - A variant of the MA5B wielded by Spartan-III's in Halo: Ghosts of Onyx.
 * MA2B ICWS/Carbine - Successor to the MA1. Functionally similar to the the MA5B. Occasionally used by Special Forces operators.
 * Asymmetric Recoilless Carbine-920 - Compact-channel linear accelerator carbine, fires high-explosive rounds at extreme velocities. Featured in Halo 4. Better known as the railgun.

Covenant

 * Type-25 Carbine - A one-handed projectile weapon, commonly used by the Jiralhanae. Featured in Halo 3 and Halo: Reach. Better known as the Spiker or Spike Rifle.
 * Type-33 Carbine - A one-handed guided munitions launcher. Featured in all Halo installments. Better known as the Needler.
 * Type-51 Carbine - A two-handed Covenant projectile weapon. Featured in Halo 2, Halo 3, Halo Wars, Halo 3: ODST and Halo 4. Better known as the Covenant Carbine.
 * Type-25 Plasma Rifle - A one-handed plasma-operated weapon typically wielded by Sangheili. Compact compared to the Type-55 Storm Rifle. Better known as the plasma rifle.
 * Type-25 Brute Plasma Rifle - Variant of the Type-25 Plasma Rifle wielded exclusively by Jiralhanae, with superior rate of fire. Featured in Halo 2 and Halo 3: ODST.