The Splatoon franchise has eleven weapon types after Splatoon 3’s additions.
The original Splatoon introduced seven main weapon classes: Shooters, Chargers, Splat Rollers, Splatlings, Inkbrushes, Blasters, and Sloshers. Splatoon 2 expanded the roster with Dualies and Brellas, bringing the total to nine.
Splatoon 3 added two more classes: Stringers, bow-like weapons that fire ink projectiles, and Splatana, blade-like weapons that can slash at close range or launch charged ink attacks. Those additions raised the franchise-wide total to eleven weapon types.
The number refers to weapon categories, not the total number of individual weapons. Each category contains multiple models, variants, and loadouts, and each weapon set can include a main weapon, a sub-weapon, and a special weapon. That distinction is why counting every purchasable weapon produces a much larger number than eleven.