A Grenade Launcher serves the role of a launcher weapon that can be used and carried by a single un-augmented human. Unlike Missile Launchers, the explosive projectiles fired from a Grenade Launcher are not self-propelled, instead taking a ballistic trajectory once fired. The grenades are typically equipped with either Frag or Krak warheads, although Grenade Launcher projectile warheads are smaller and less powerful than the Missile Launcher warhead equivalents.
Grenade Launchers are used most commonly by the Astra Militarum, although Inquisitorial Storm Troopers, Adeptus Arbites and Adeptus Astartes units are also known to use them. Grenade Launchers can fire a variety of grenade types but generally at a shorter range than other basic weapons due to the heavier nature of their payload. Unlike most weapons they can be fired in arcing shots designed to clear obstructions and strike farther into an enemy formation as well as simply being fired directly at foes. The common Voss Grenade Launcher holds a magazine of six grenades, but most find the weapon inaccurate even for a launcher. The Forge World of Mezoa produces what many believe is a superior shoulder-mounted weapon with a longer range, for though it is a single-shot device it has superior firing systems and is highly accurate.
- Astartes Grenade Launcher - Often employed by Scout Bikeers, Astartes Grenade Launchers are outfitted with adaptive targeters to compensate for the high speeds at which they hurl themselves at the enemy. A wrist-mounted variant is utilised by Terminators.
- Assault Grenade Launcher - A robust, if short-ranged, belt-fed weapon, the Grenade Launcher carried by the Death Guard's Grave Wardens was a modified pattern designed primarily for mounting on vehicles of the Imperial Army. It carried two kinds of ammunition: one was a standard shaped-charge Krak shell and the other a toxic warhead which unleashed a burst of highly lethal chemical agents and concentrated acidic vapour on detonation.
- Auxiliary Grenade Launcher - A small single-shot version of the standard Imperial Grenade Launcher fitted onto another ranged weapon such as a Lasgun, Bolter or Autogun, allowing the user to fire a single grenade instead of firing the weapon as normal. The added weight and cumbersome nature of this Grenade Launcher means that most users rarely bother to reload the launcher once it is expended. An Auxiliary Grenade Launcher can be fitted to any basic Imperial ranged weapon. When a Space Marine's enhanced strength is not adequate to propel his choice of grenades far enough, an Auxiliary Grenade Launcher can be employed. These compact tubes hold a small row of pre-primed grenades. An Auxiliary Grenade Launcher is most commonly mounted above or below the barrel of a basic ranged weapon in a manner similar to a Combi-weapon. However, models with standalone trigger mechanisms are also available.
- Blackstar Cluster Launcher - Utilised exclusively by the Space Marines of the Deathwatch, the Corvus Blackstar has two rear-mounted Grenade Launchers, allowing the pilot to sow a hailstorm of munitions in his wake as he strafes his primary targets. The launcher is capable of firing either crater-chewing frag clusters or a matrix of infernus grenades that leave burning Promethium in the Blackstar's wake.
- Cadian Pattern Grenade Launcher - The Cadian Pattern Grenade Launcher is a commonly used variant utilised by the Cadian Shock Troops Astra Militarum regiment. It can carry a load of twenty grenades and pivots forward to allow reloading. To aim the weapon, the Guardsman flips up a rear sight, which is notched for different ranges, and matches this up with the weapon's front quadrant sight. When preparing to pull the trigger, a Guardsman must first brace himself with a wide-legged stance, as the recoil from Grenade Launchers is significant, comparable to that of a Bolter, and recoil injuries are a common occurrence amongst Guardsmen unfamiliar with the weapon's power.
- Elysian Pattern Grenade Launcher - The Mark IVc Lasgun is a variant las weapon utilised exclusively by the Elysian Drop Troops of the Astra Militarum. This Grenade Launcher also includes an auxiliary Krak Grenade Launcher mounted under the barrel. This is a short-range, single shot weapon, issued to officers and non-commissioned officers for additional squad-level close support.
- Mezoa Pattern Grenade Launcher - The Forge World of Mezoa produces what many believe to be a superior shoulder-mounted weapon with a longer range, for though it is a single shot device it has superior firing systems and is highly accurate.
- Voss Pattern Grenade Launcher - A common variant of the Grenade Launcher manufactured by the Forge World of Voss, the Voss Pattern holds a clip of six grenades, but most find the weapon inaccurate even for a launcher.
- Tauros Grenade Launcher - The Tauros Grenade Launcher is a single, pintle-mounted, rapid-firing variant of the weapon utilised by Astra Militarum regiments on the Tauros all-terrain vehicle.
- Codex Adeptus Astartes - Space Marines (8th Edition), pp. 77, 87, 112, 140
- Codex: Deathwatch (7th Edition), pp. 45, 104
- Codex: Space Marines (7th Edition) (Digital Edition), "Armoury of the Space Marines - Ranged Weapons - Astartes Grenade Launcher", pg. 426
- Codex: Space Marines (6th Edition) (Digital Edition), pg. 413
- Dark Heresy: Core Rulebook (RPG), pg. 136
- Dark Heresy: The Inquisitor's Handbook (RPG), pg. 174
- Deathwatch: Core Rulebook (RPG), pg. 152
- Imperial Armour Volume One - Second Edition: Imperial Guard, pg. 228
- Imperial Armour Volume Three - The Taros Campaign, pp. 80, 112, 272
- Imperial Armour Volume Four - The Anphelion Project, Pg. 136
- Imperial Armour Volume Five - The Siege of Vraks - Part One, pg. 95
- Imperial Armour Volume Eleven - The Doom of Mymeara, pg. 101
- Imperium Munitorum Manual (Background Book) by Graham McNeill, pg. 74
- Only War: Hammer of the Emperor (RPG), pg. 114
- Rogue Trader: Core Rulebook (RPG), pg. 125
- The Horus Heresy - Book Two: Massacre (Forge World Series) by Alan Bligh, pg. 227
- The Horus Heresy - Book Four: Conquest (Forge World Series) by Alan Bligh, pp. 154, 247
- The Horus Heresy - Book Five: Tempest (Forge World) by Alan Bligh, pg. 180
- Warhammer 40,000: Rogue Trader (1st Edition), pg. 84
- Warhammer 40,000: Wargear (2nd Edition), pp. 21, 25