In Splatoon 3, a variety of badges can be earned through achievements and playing the game, and up to three of them can be displayed at once on the bottom-right corner of a player's Splashtag.
Badges are awarded for fulfilling certain criteria such as getting 50 Turf War wins, earning 10,000 Grizzco points and defeating DJ Octavio in Return of the Mammalians. Some Badges have multiple tiers, such as 4- and 5-star weapon freshness. Some Splatfest-related achievements, such as reaching Ruler rank, also reward badges.
Callie and Marie's badges are the only ones who share an unlock requirement.
It is currently impossible to obtain the second level of brand badges for any brand, as there are not enough pieces of matching gear in the game. Accumulating 100 total stars across all of a brand's gear requires at least 20 gear items of a single brand, and the most any non-amiibo brand has as of 1.2.1 is Krak-On at 16 items.