Squidward Quincy Tentacles ( /ˈskwɪd.wərd/, /ˈskwɛd.wərd/) is a fictional character in Nickelodeon's animated television series SpongeBob SquarePants. Created and designed by marine biologist and animator Stephen Hillenburg, he is voiced by actor Rodger Bumpass. Squidward first appeared on television in the series' pilot episode "Help Wanted" on May 1, 1999.

Despite having "squid" in the character's name, Squidward is an anthropomorphic octopus. He lives in a moai themed house between SpongeBob SquarePants' and Patrick Star's houses on Conch Street in Bikini Bottom. The character is portrayed as short-tempered, impatient, arrogant, selfish, sassy, introverted, condescending, bitter, and misanthropic, and he despises his two neighbors' constant disruptive antics. However, the pair are unaware of Squidward's dislike towards them and see him as a friend. Squidward works as a cashier at the Krusty Krab restaurant, a job which he does not enjoy.

The character's reception from fans has been positive. Squidward is a recurring character in all of the franchise's theatrical and streaming films starting with The SpongeBob SquarePants Movie, and has appeared in many SpongeBob SquarePants publications, toys, and other merchandise.

Stephen Hillenburg first became fascinated with the ocean and began developing his artistic abilities as a child. During college, he majored in marine biology and minored in art. After graduating in 1984, he joined the Ocean Institute, an ocean education organization, where he had the idea to create a comic book titled The Intertidal Zone, which led to the creation of SpongeBob SquarePants. In 1987, Hillenburg left the institute to pursue a career in animation.

Several years after studying experimental animation at the California Institute of the Arts, Hillenburg met Joe Murray, creator of Rocko's Modern Life, at an animation festival. Murray offered Hillenburg a job as a director of the series. Martin Olson, one of the writers for Rocko's Modern Life, read The Intertidal Zone and encouraged Hillenburg to create a television series with a similar concept. At that point, Hillenburg had not considered creating his own series, but soon realized that this was his chance. Shortly after production on Rocko's Modern Life ended in 1996, Hillenburg began working on SpongeBob SquarePants.

Hillenburg used some character designs from his comic book. He designed "SpongeBob's grumpy next door neighbor" as an octopus because he liked the species' large head, noting that Squidward "thinks he's an intellectual". Instead of the usual eight limbs, Hillenburg explained that Squidward is normally drawn with six limbs as it was "just simpler" to animate him that way. Squidward is only shown with a full set of eight tentacles in two episodes: the live-action sequence in "Pressure" from season two, and briefly in "Sold!" from season nine. Hillenburg named the character Squidward after the squid, which is closely related to the octopus and has ten limbs, and the English name, Edward. In the words of Squidward's voice actor Rodger Bumpass, the name Octoward "just didn't work".

Of Squidward's design, show writer and storyboard artist Vincent Waller said in 2010:

Squidward is hard to draw—he has a very odd-shaped head. Fortunately, his emotions are pretty even, but to get a whole lot of big emoting out of him is a challenge. His nose splits everything in half, so it's always like, 'OK, how am I going to work this and still make it read?'