The second season of the American animated television series SpongeBob SquarePants, created by Stephen Hillenburg, aired on Nickelodeon from October 20, 2000, to July 26, 2003, and consists of 20 half-hour episodes. The series chronicles the exploits and adventures of the title character and his various friends in the fictional underwater city of Bikini Bottom. The season was executive produced by series creator Hillenburg, who also acted as the showrunner.

During the season's run, SpongeBob SquarePants became Nickelodeon's No. 2 children's program, behind Rugrats. Nearly 40 percent of SpongeBob's audience of 2.2 million were aged 18 to 34. The show also found financial success in merchandising, having signed marketing deals with various retail companies. In 2002, the show was nominated at the Primetime Emmy Awards for Outstanding Children's Program. Tom Kenny and Mary Jo Catlett were individually nominated at the 29th Annie Awards for their voice performances as SpongeBob and Mrs. Puff, respectively. Peter Straus and Paul Tibbitt were also nominated at the ceremony for their work on the "Christmas Who?" special. The episodes "The Secret Box" and "Band Geeks" won at the 2002 Golden Reel Awards for Best Sound Editing in Television—Animation, while the episodes "Jellyfish Hunter" and "The Fry Cook Games" received a nomination for Best Sound Editing in Television Animation—Music category.

The SpongeBob SquarePants: The Complete 2nd Season DVD was released in Region 1 on October 19, 2004, Region 2 on October 23, 2006, and Region 4 on November 30, 2006. Several compilation DVDs that contained episodes from the season were released prior and after.

The season's executive producer was series creator Stephen Hillenburg, who also functioned as the series' showrunner. During production of the previous season, Nickelodeon picked up a second season for SpongeBob SquarePants on August 31, 1999. The season premiered more than a year later, on October 20, 2000. Season production assistant Derek Iversen commented, "We hoped it would go one season. We hoped it would go two seasons. I figured you do the best you can and you hope."

In this season, production switched from cel animation, used during the first season, to digital ink and paint. Executive producer Paul Tibbitt, in 2009, said "The first season of SpongeBob was done the old-fashioned way on cells, and every cell had to be part-painted, left to dry, paint some other colours. It's still a time-consuming aspect of the process now, but the digital way of doing things means it doesn't take long to correct." The animation was handled overseas in South Korea at Rough Draft Studios. Animation directors credited with episodes in the second season included Sean Dempsey, Edgar Larrazabal, Larry Leichliter, Andrew Overtoom, Leonard Robinson, Frank Weiss, and Tom Yasumi. The season was storyboarded by Walt Dohrn, C.H. Greenblatt, Chris Headrick, Chuck Klein, Carson Kugler, Jay Lender, Caleb Meurer, Dan Povenmire, William "Bill" Reiss, Octavio Rodriguez, Jim Schumann, Aaron Springer, Paul Tibbitt, and Erik Wiese. Episodes were written by a team of writers, which consisted of Dohrn, David Fain, Greenblatt, Mr. Lawrence, Lender, Mark O'Hare, Povenmire, William Reiss, Springer, Tibbitt, and Merriwether Williams.

During the season, the writing staff used their individual childhood experiences as inspirations to come up with much of the story lines for individual episodes. For example, the idea for the plotline of the episode "Sailor Mouth" was inspired by creative director Derek Drymon's experience when he "got in trouble for saying the f-word in front of [his] mother." Drymon cited two scenes which were reflective of his experiences, including the scene "where Patrick is running to Mr. Krabs to tattle, with SpongeBob chasing him," and the end of the episode, where Mr. Krabs uses more profanity than SpongeBob and Patrick, as Drymon's mother "has a sailor mouth herself." In "The Secret Box", SpongeBob wants to see what is inside Patrick's secret box. The idea came to Drymon because he too had a secret box as a child. Creator Hillenburg said that the staff "wanted to make fun of him and use [the story]" after he brought it up.

The second season featured Tom Kenny as the voice of the title character SpongeBob SquarePants and his pet snail Gary. SpongeBob's best friend, a starfish named Patrick Star, was voiced by Bill Fagerbakke, while Rodger Bumpass played the voice of Squidward Tentacles, an arrogant and ill-tempered octopus. Other members of the cast were Clancy Brown as Mr. Krabs, a miserly crab obsessed with money and SpongeBob's boss at the Krusty Krab; Mr. Lawrence as Plankton, a small green copepod and Mr. Krabs' business rival; Jill Talley as Karen, Plankton's sentient computer sidekick; Carolyn Lawrence as Sandy Cheeks, a squirrel from Texas; Mary Jo Catlett as Mrs. Puff, SpongeBob's boating school teacher; and Lori Alan as Pearl, a teenage whale who is Mr. Krabs' daughter.

Season two introduced various characters that would recur throughout the series. Mr. Krabs' mother, Mama Krabs, debuted in the episode "Sailor Mouth" and was voiced by writer Paul Tibbitt. However, voice actress Sirena Irwin overtook Tibbitt's role as the character reappeared in the fourth season episode "Enemy In-Law" in 2005. In the Christmas special "Christmas Who?", SpongeBob's voice actor, Tom Kenny, portrayed Patchy the Pirate, the president of the fictional SpongeBob SquarePants fan club, while series creator Hillenburg voiced the character of Potty the Parrot. After Hillenburg's departure from the show as showrunner in 2004, Tibbitt was given the role voicing Potty the Parrot.