Melee is the tertiary category weapon in Counter-Strike Online.
The seal knife is available to all players by default while the other melee weapons are purchasable with game points or cash points. Most melee weapons movement speed is 250 units per second, meaning they suffer no speed reduction. Every player starts out with the seal knife (provided they haven't brought another melee weapon yet); unlike the primary and secondary weapons, it cannot be dropped.
- Main article: Seal knife.
Seal knife is the default melee weapon in Counter-Strike series and Counter-Strike Online. It is available for free to every players. Seal knife is usually being used in close combat situations, stealth kills and rushing tactics. It is undroppable. This weapon are belonged to all male characters as their spawn melee weapon by default. This weapon can do instant kill if a backstab or headshot is scored.
- Main article: Cold Steel knife.
The Cold Steel Knife is the spawn weapon for every female characters in Counter-Strike Online. The Cold Steel Knife has the same function as the Seal knife. It is used when the player is using female characters only.
- Main article: Hunting Dagger.
The Hunting Dagger is purchasable with game points and possess a slight advantage from the seal knife. It has higher swing rate than the seal knife. Note that the hunting dagger uses Counter-Strike: Condition Zero knife animation.
- Main article: Balisong.
Balisong has high swing rate even for stabbing but it is purchasable by cash points only and it does lower damage to enemy. It takes three stabs to kill an enemy instead of the seal knife's two. Recommended for Zombie Scenario in bonus rounds.
- Main article: Parang.
Sabit (or Parang in game or Axe for certain countries) does very high damage to enemies. It can kill an enemy with just two hits from the front. Moreover, it can kill an enemy with just single hit on the back. Sabit is recommended for knife battles.
- Main article: Nata Knife.
- Main article: Dragon Claw.
Dragon Claw is a melee weapon in Counter-Strike Online obtainable randomly from Code Box. This is the first dual-wielded melee introduced in Counter-Strike Online series.
- Main article: Combat knife.
Combat knife is a melee weapon that is able to deal very high damage to enemies, it is purchasable with cash points. It has a improved variant called Master Combat knife.
- Main article: Master Combat knife.
The upgraded version of Combat Knife can only be obtainable from it's upgrade event. It has longer range and does higher damage than the original weapon. The user can easily attack enemies from a relatively safe distance.
- Main article: SKULL-9.
- Main article: Dragon Knife.
Dragon Knife is a special melee weapon that shares same stats to the seal knife. It is only available during Chinese New Year event.
- Main article: Wakizashi.
Wakizashi or Katana has further attack range then most melee weapons and can kill an enemy with just one slash. However, it is heavier than most melee weapons.
- Main article: Dual Wakizashi.
Dual Wakizashi or Dual Katana is the upgraded version of Wakizashi, it has the same propeties but it's dual wielded and slashes faster than the single wielded variant.
- Main article: Tomahawk.
Tomahawk is a special melee weapon in use by the Special Forces, it has slow swing rate, but makes it up by having a good killing power.
- Main article: Dual Nata Knives.
Dual Nata Knives can only be obtained randomly by Sidekicks in Zombie 3: Hero and has higher damage than the single-wielded Nata Knife. It is a couple of knives on a syringe handle with some sort of Poison Gun. It has faster slashing rate in primary mode.
- Main article: Green Dragon Blade.
Green Dragon Blade or Guan Yu Blade is a melee part of Dragon firearms. It has the ability to kill multiple targets with a single slash, similar to Skull-9. There are many aspects where it is similar to Skull-9. This melee is obtainable from Bingo Event and Code Box.
- Main article: Serpent Blade.
- Main article: Beam Sword.
Beam Sword is a science fiction melee weapon made by an unknown technology. It can glow in the dark and the user can turn off the light to increase movement speed. Only obtainable through Bingo Event.
- Main article: Joker's Staff.
The Joker's Staff is the only melee weapon which can be used by the Joker in Hidden mode. Its primary attack can kill a human with 3 slashes while 1 slash in secondary mode. Note that in secondary mode, there is a slight attack delay.
- Main article: Shelter Axe.
An alternate skin for Tomahawk. It serves as the default melee weapon in Zombie Shelter and the player must use it to collect resources and attack enemies.
- Main article: Machete.
A knife used to make a jungle road in the jungle. You can use it for logging woods. It is thick and boasts a durable, strong power.
- Main article: Crowbar.
A tool used to pull nails. Surprisingly, its hardness makes it a powerful weapon.
- Main article: Claw Hammer.
Claw Hammer is used for construction modifications to maintain combat weapon specific.
- Main article: JANUS-9.
This is a melee weapon developed by Aegis Institute. It is equipped with Janus Transformation System that can be activated after the user has attacked the enemies for several times with this weapon. Janus form can deal a great damage to enemies.
- Main Article: Ruyi Stick.
This is the stick rumored used by the Monkey King, Sun Wukong. Its length can be increased according to situation.
- Main article: Crowbar Maverick.
This modification was made by an unknown Terrorist group to be used as a demolition tool as well as an normal crowbar to remove nails. The major change noted is the addition of a taser to improve its efficiency when taking down targets.
- Main article: Papin.
This is a steampunk pair of gauntlets that can unleash a powerful ranged attack accumulated by the steam mechanism.
- Main Article: Oz Scarecrow Pickaxe.
This is a scarecrow-shaped pickaxe that turned into a weapon, renovated entirely for swinging purpose.
- Main Article: THANATOS-9.
This is a melee weapon developed by Aegis Institute in form of a scythe. It is incorporated with continuous separation technique that allows the user to perform a flurry of stabs whenever Thanatos Blade System is in use.
- Main Article: VULCANUS-9.
A special sword developed by Aegis Institute and applied with Vulcanus Parts System. When the gas line parts are activated, it can deal tremendous damage to enemies.
- Main Article: Heavy Zombie Knife.
A cleaver wielded by the Heavy zombie. It is short and very heavy.
- Main Article: Storm Giant Warhammer.
A huge breath of life filled with overwhelming power of the ancient giant storm is transferred to the owner by simply holding this hammer with both hands. If in possession, the user will be granted with the following buffs:
- Draw attack: the user performs a quick strike whilst drawing the weapon.
- Combination attack: the user can perform a chained attack by pressing (default) upon drawing the hammer.
- Drawing out melee weapon results a sound that can be heard in predetermined distance. Despite of revealing presence, it can be useful to lure one or few players.
- Melee weapons do lower damage in Frag War submode.