List of characters
From SpongePedia, the First SpongeBob Wiki.
 Main characters
There are ten main characters in the series.
- SpongeBob SquarePants (voiced by Tom Kenny) — An optimistic yellow sea sponge who works as a fry cook at the Krusty Krab. He is perpetually enrolled in boating school. He debuts in "Help Wanted."
- Patrick Star (voiced by Bill Fagerbakke) — SpongeBob's best friend, a dimwitted yet pleasant pink starfish. He tends to unintentionally land himself and SpongeBob in trouble. He debuts in "Help Wanted."
- Squidward Tentacles (voiced by Rodger Bumpass) — An octopus who is the pessimistic coworker and neighbor of SpongeBob. He enjoys interpretive dance and playing the clarinet. He debuts in "Help Wanted."
- Mr. Krabs (voiced by Clancy Brown) — The owner of the Krusty Krab and SpongeBob's employer. He talks like a pirate and has an obsession for money. He debuts in "Help Wanted."
- Sheldon Plankton (voiced by Doug Lawrence) — An evil planktonic copepod who wants to run the Krusty Krab out of business. He runs the unsuccessful Chum Bucket restaurant. He debuts in "Plankton!"
- Karen Plankton (voiced by Jill Talley) — Plankton's sentient computer sidekick who gives him his evil plans. She is far more competent than Plankton. She debuts in "Plankton!"
- Sandy Cheeks (voiced by Carolyn Lawrence) — A squirrel from the surface who befriends SpongeBob and lives in a glass dome full of air. She debuts in "Tea at the Treedome."
- Mrs. Puff (voiced by Mary Jo Catlett) — A patient and elderly pufferfish who is SpongeBob's boating school teacher. She is currently dating Mr. Krabs. She debuts in "Boating School."
- Pearl Krabs (voiced by Lori Alan) — A teenage whale who is Mr. Krabs' daughter. She will inherit the Krusty Krab and become its owner when she grows older. She debuts in "Squeaky Boots."
- Gary the Snail (voiced by Tom Kenny) — SpongeBob's pet sea snail, who communicates by meowing like a cat. He often proves to be more clever than his owner. He debuts in "Help Wanted."
 Recurring characters
- Patchy the Pirate (played by Tom Kenny) — A pirate who runs the fictional SpongeBob SquarePants fan club. He is the host of most special episodes. He debuts in "Christmas Who?"
- Potty the Parrot (voiced by Stephen Hillenburg and later Paul Tibbitt) — Patchy's sarcastic pet parrot. She is portrayed as a poorly-made puppet with obvious strings. She debuts in "Christmas Who?"
- The French Narrator (voiced by Tom Kenny) — An ocean explorer who narrates many episodes as if they were documentaries about the sea. He debuts in "Help Wanted."
- Mermaid Man and Barnacle Boy (voiced by Ernest Borgnine and Tim Conway) — A duo of semi-retired superheroes who previously starred in a television show. They debut in "Mermaid Man and Barnacle Boy."
- The Dirty Bubble (voiced by Charles Nelson Reilly and Tom Kenny) — Mermaid Man and Barnacle Boy's greatest enemy. He debuts in "Mermaid Man and Barnacle Boy II."
- Man Ray (voiced by John Rhys-Davies and Bob Joles) — Mermaid Man and Barnacle Boy's other nemesis. He debuts in "Mermaid Man and Barnacle Boy III."
- Larry the Lobster (voiced by Doug Lawrence) — A bodybuilder and workout fanatic who occasionally appears in beach-themed episodes. He debuts in "Ripped Pants."
- The Flying Dutchman (voiced by Brian Doyle-Murray) — A ghost pirate who haunts the seas and owns a glowing ship that floats above Bikini Bottom. He debuts in "Scaredy Pants."
- King Neptune (voiced by John O'Hurley and Jeffrey Tambor) — A merman god who rules the sea and possesses magical powers. He debuts in "Neptune's Spatula."
- Realistic Fish Head (voiced by Doug Lawrence) — A trout who appears in the opening sequence and hosts various news programs in the series. He debuts in "Mermaid Man and Barnacle Boy II."