During season 1, the sheet only featured eight character models, in order: Sandy in her bathing suit, Sandy in her diving suit, SpongeBob, Patrick, Squidward, Mr. Krabs, Mrs. Puff, and Pearl. The main character models for the first season.

The first other characters Hillenburg created were Patrick the starfish, Mr. Krabs the crab, Pearl ...

SpongeBob SquarePants (character) List of characters/Main; Patrick Star; Squidward Tentacles; Sheldon J. Plankton; Sandy Cheeks; Eugene H. Krabs; King Neptune; All items (1830) # A; B; C; D; E; F; G; H; I; J; K; L; M; N; O; P; Q; R; S; T; U; V; W; X; Y; Z; Other

Abrasive Sponge • BlackJack • Captain Blue SquarePants • Clever Visual Metaphor for the Abstract Concept of Thought • Drifter • Employee of the Month SpongeBobs • Ensign • Girly Teengirl • Grandma SquarePants • Giant SpongeBob • Grandpa SquarePants • Harold SquarePants • Margaret SquarePants • Primitive Sponge • RandomLand SpongeBob • Sherm SquarePants • Snow sponge • Spongezilla • SpongeBob's grandson • SpongeBob SquarePants • SpongeBob SquarePants ...

In addition to the ten main characters, SpongeBob SquarePants has over 300 background characters. They are identified by the artists and animators with individual model numbers. These model numbers correspond to when the characters were designed in production. The following is a list of background characters, sorted by their model numbers.