This article is a list of the members of SpongeBob SquarePants' family tree, listed in the order of their first (or only) appearance.

Image Name Voice actor Description
Mr. & Mrs. Squarepants2 Harold and Margaret SquarePants Tom Kenny and Sirena Irwin SpongeBob's parents, first seen in the episode "Home Sweet Pineapple". Oddly enough, they bare more resemblance to actual ocean sponges than SpongeBob himself.
Grandpa SquarePants Grandpa SquarePants Tom Kenny SpongeBob's paternal grandfather is first mentioned in "Rock Bottom" and appears in SpongeBob's mind in "The Sponge Who Could Fly". He is known for his wise sayings, which include "If we were meant to fly, we'd have propellers on our backs," and "Never run for a bus, especially one that's going up at a 90 degree angle."
Spongetron SpongeTron Tom Kenny SpongeTron is a robot descendant of SpongeBob who lives during the 41st century, seen in the episode "SB-129". When Squidward arrived in the future, he shortly met SpongeTron and some of his clones in the kitchen area of the Krusty Krab. There are 486 SpongeTrons in total. SpongeTron's legs are rockets, which allow them to hover over the floor. They also can pull their ties to make an robotic arm come put of their hats holding a brick and then they drop. SpongeTron's best friend is Patron (a two-headed descendant of Patrick).
No Image Primitive Sponge Tom Kenny This primitive sponge is SpongeBob's earliest-known ancestor, seen in the episode "SB-129" when Squidward travels back to prehistoric time.
Grandmas Kisses Grandma SquarePants Marion Ross SpongeBob's paternal grandmother, first seen in the episode "Grandma's Kisses".
Sherm Sherman "Sherm" SquarePants N/A Sherman SquarePants is a sometimes-mentioned uncle of SpongeBob's, though he has never made a physical appearance, instead only being seen in photos. He is first mentioned in "Krab Borg" and is seen in a photo in "Pest of the West".
Spongegar SpongeGar Tom Kenny SpongeBob's caveman ancestor is more curious and smarter than his primitive ancestor. He is also more advanced than the Primitive Sponge because he has developed clothes, a language system, domestication, and a curiosity for new discoveries, such as cooking food.
CousinBlackJack BlackJack SquarePants John DiMaggio BlackJack is SpongeBob's muscular cousin who is the main antagonist of the episode "BlackJack". In the episode, SpongeBob receives a note from his cousin BlackJack, saying that he is going to pay him a visit. SpongeBob is shown to greatly fear BlackJack, because BlackJack always picked on them when he was little, and was even arrested for littering. Fortunately, when SpongeBob does confront BlackJack at the end of the episode, it is revealed that BlackJack is no bigger than Plankton and thus cannot actually harm SpongeBob.
Captain Blue Captain Blue SquarePants Garnett Sailor Uncle Captain Blue is a retired police captain who is SpongeBob's uncle, seen only in the episode "BlackJack". He is quite lazy, and enjoys drinking Clam Tomato Chowder Juice, listening to country music on his old record player, and talking on a CB radio.
Stanley S. SquarePants Stanley S. SquarePants Stanley, who appears only in a self-titled episode, is SpongeBob's accident-prone cousin who destroys everything he touches. Uncle Sherm sends Stanley to SpongeBob's house to see if he can take care of him. Stanley then goes to the Krusty Krab because he is jealous of SpongeBob having a job.
WestBob SpongeBuck SquarePants Tom Kenny SpongeBuck is SpongeBob's ancestor who appears in the episode "Pest of the West". He was an old Western hero who lived in Dead Eye Gulch and sometimes hung out at the Krusty Kantina. He rescued Dead Eye Gulch from being taken over by Dead Eye Plankton (Plankton's ancestor) in 1870, the "Wild West" period. He was best friends with Pecos Patrick, the cowboy ancestor of Patrick.
SpongeBrian-SpongeKevin-SpongeCarl SpongeBrian, SpongeKevin, and SpongeCarl N/A These three nephews of SpongeBob appear in the comic "My Nephews Are Coming to Visit". In the story, they come to Bikini Bottom to visit their uncle SpongeBob. However, they find everything boring in the city and begin to irritate the inhabitants. In a piece of irony, though, they enjoy Squidward's hobbies. They are parodies of Donald Duck's nephews, Huey, Dewey and Louie.
Todd SquarePants Todd SquarePants N/A Todd is SpongeBob's long-lost, very slobby cousin, who appears only in the book The Never-Ending Stay.
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