The fourth season of iCarly began airing on Nickelodeon July 30, 2010, and ended on June 11, 2011. The season features Carly Shay (Miranda Cosgrove), Sam Puckett (Jennette McCurdy) and Freddie Benson (Nathan Kress) as their own Web Show iCarly is becoming more popular worldwide. Jerry Trainor co-stars as Carly's big brother Spencer. Noah Munck joins the main cast this season as Gibby Gibson. The specials of the season include "iGot a Hot Room", "iSam's Mom", "iDo", "iStart a Fan War", "iOMG", and "iParty with Victorious".
 Caitlin Carmichael as Molly ("iPity the Nevel")
 Starting from this season onwards, Gibby begins to hang out more often with Carly, Sam and Freddie than in the past three seasons.
 In November of this season, the iCarly crew accidentally starts a fan war at WebiCon over who should date, Carly and Freddie (Creddie), or Sam and Freddie (Seddie). Despite the three confirming that none of them are dating, the fan war still seemingly remains unresolved. However, five months later, the three complete their two-month search for an intern for iCarly, at which point Sam — much to Carly's and Freddie's confusion and suspiciousness — begins hanging out with Freddie and Brad, the new intern, every time she gets the chance to. When Freddie tests his selfmade "MoodFace" app on Sam, it confirms that she is actually in love. Thinking that Sam still hates Freddie, he and Carly misunderstand the results, believing that Sam is in love with Brad, and Carly takes great steps into proving this. Sam still tries to convince her that she is not in love with him though. Freddie later finds Sam in the school yard and gives her a heart-to-heart talk about opening up and taking a risk when it comes to romantic feelings, not realizing that he is actually referring to himself. In the middle of the talk, Sam grabs Freddie and kisses him passionately, revealing that in fact he is the one she is in love with, as a shocked Carly watches through the window.
 
 Spencer wants to make Carly's 16th birthday the best ever. After getting his haircut at Carly's request from Gibby's visually impaired grandfather, he makes a gummy bear lamp and puts it in Carly's room, but it later sets her room on fire. However, Spencer receives $82,000 in an insurance settlement after hearing their great-grandmother's expensive diamond-encrusted bezel watch was destroyed in the fire. Spencer makes Carly get a job at the Groovy Smoothie while he, Sam, Freddie, Gibby, and a bunch of workers, engineers, and technologists work to put a new room for Carly. Things in the new room include a makeup station, a computerized wardrobe, and a gummy bear chandelier (made from fireproof gummy bears).
 Guest stars: Jack Carter as Gilbert Gibson (Gibby's Grandfather), BooG!e as T-Bo, David Dean Bottrell as Bob, Stephen Jared as Chief Donker
 After an argument with her mother, Sam moves in with Carly and Spencer. When Sam's unfortunate habits and messy living conditions become a problem, Carly invites Pam, Sam's mother, to the apartment so she and her daughter could resolve their problems. The solution becomes an enormous argument, in which the Shay sofa gets thrown into the kitchen by Sam and her mother. Sam and Pam go to therapy and are locked in a tiny room called a therapy box, in which they are not set free unless they make up and act nice. The therapist figures Carly can talk some sense into them, and locks Carly with the ladies, in which Carly eventually fakes an unfortunate claustrophobic attack while in such a small space in order to convince Sam to admit she loves her mother. Pam and Sam emotionally make up and hug, with a happy ending. Meanwhile, Freddie becomes trapped in danger after a criminal who he unmasked at Groovy Smoothie discovers his address and identification. So he and Mrs. Benson hide in Carly and Spencer's apartment, along with a body guard who was in the army. This annoys Spencer into switching the numbers on Freddie's door with the ones on the door down the hall, which successfully works when the criminal comes to seek revenge. 
 Special guest star: Jane Lynch as Pam Puckett,
 After showing their viewers of iCarly a bloody pickle prank video this leads to talking of pranks. Sam and Freddie have pulled great pranks except Carly causing Sam and Freddie to tell her that knock knock jokes and pranking Lewbert do not count and make fun of her and forcing her to prank someone. After a few unsuccessful attempts, Carly asks Spencer to help her prank Freddie and Sam. Although reluctant due to a traumatic pranking experience in high school 14 years earlier which involved dumping garlic powder on many kids' eyes, Spencer agrees to help out. Though the prank goes off without a hitch, Spencer cannot stop pranking people afterwards to everyone's annoyance and Carly, Sam and Freddie fail to outsmart him with a prank of their own. In the end, Carly gets the kids from Spencer's high school to come to their house to convince him to stop pranking. Carly goes upstairs to get her video camera to record the events, but by the time she gets down, the adult kids beat up Spencer as revenge, and rush out when Carly catches them. Spencer then admits he understands how bad pranking can be.
 When Carly, Sam and Freddie's penny tees are a hit, they decide to go into business to make them, so when Sam decides to hire fourth graders from a bible school to make the Penny Tees, Sam and Freddie both get different ideas on how to treat the children when she works the kids aggressively in deplorable warehouse conditions. Later in the episode, Sam splits the kids up and kids with last names from N-Z go to Carly and other kids stay with Sam. Carly and Freddie's kids think that it is all about breaks and having fun, and when they only make 6 tees in 1 day, Carly and Freddie stop the business. The kids with last names from A-M quit Sam's business as well, having had enough of the unfair work conditions In the end, they try to give the kids a second chance but it turns out they already started their own Penny Tee business and hired writers their age. Meanwhile in the episode, Spencer dates a girl from Uzbekistan. Spencer does not understand what she says, since she does not speak a word of English. However he tells Gibby to bring over his bus driver also from Uzbekistan but since he also does not speak English, the girl ends up going out with the bus driver instead.
 A fan of iCarly plans on getting married, but everything takes a wrong turn when the groom gets cold feet; Gibby enlists the help of an old woman to help him get a five dollar bill out of a tree.
 The iCarly team is going to Webicon (an awards show for websites and other things on the internet) and they accidentally start a fan war, a war between fans thanks to Sam. The fans are divided who should end up together: Carly and Freddie (Creddie) or Sam and Freddie (Seddie). Meanwhile Spencer faces battle-to-battle with his online gaming nemesis, Asparatamay (Jack Black) and when Aspartamay finds out his opponent Aruthur has a sister he tries to destroy her. As a sub-plot, Gibby's grandfather is supposed to go to Webicon along with Gibby and Guppy but he complains that wants to have soup first. Sam becomes obsessed with Fat Shakes like her favourite snack the Fat Cakes.

 Special guest star: Jack Black as Aspartamay
Special guest appearances by: Alec Medlock as Craig, Scott Halberstadt as Eric, Jake Farrow as Gavin (from Drake & Josh) and Abby Wilde as Stacey Dillsen (from Zoey 101).
Guest stars: Jack Carter as Gilbert Gibson (Gibby's Grandfather), Ethan Munck as Guppy, Max Ehrich as Adam, David Boat as Nolan
Co-stars: Marlane Barnes as Tina, Cathy Baron as Sheena, Ryan Bates as David, Nick Clark as Kenny, Kal Mansoor as Ado, Griffin Anglin as Background Chanter #1, Stephanie Cicero as Background Chanter #2, Joe Clark as Background Chanter #3, Francesca Ellana as Background Chanter #4, Gil L. Aroy as Background Chanter #5, John Reha as W.O.W. Fan #1, Mark Antani as W.O.W. Fan #2, Andrea Swain as W.O.W. Fan #3, Nick Armstrong as Warlords Booth Worker, Kent Avenido as Blow Far Nerd, Morgan Bateman as Stunt Fan #1, Matt Deadrick as Stunt Fan #2, Chad Carleton as Bell Pole Player, Matthew Landon as Red Skybot (uncredited)
 Exhausted by the work needed to run iCarly, the cast holds interviews for a new intern and offer college credit. One candidate, Brad, who shares an interest in technology with Freddie and makes fudge for everyone, is deemed the perfect candidate, but later on, Sam and Carly find an interviewee named Cort who is extremely attractive and hire him on the spot, despite the fact that he is obviously very incompetent and unintelligent. Cort immediately starts causing problems at iCarly such as pouring lemonade from a plastic bag over Freddie's laptop and scribbling marker over his PearPad, and Freddie insists that he should be fired. Carly and Sam refuse, so Freddie decides to hire an extremely attractive but dumb girl named Ashley as an intern. Cort and Ashley both make too much trouble with their stupidity, so Freddie offers to fire Ashley if the girls agree to fire Cort. Sam and Carly agree and both interns are fired and Cort admits that he was actually kicked out of college because the teachers said he was "dangerously stupid." However as she is leaving, Ashley is revealed to be actually intelligent and only pretended to be dumb for a sociology assignment, meaning that Freddie tricked Carly and Sam. Meanwhile, Spencer tries to sneak his Bottle Bot sculpture into an art museum to prevent his grandfather from making him go back to law school.
 Guest stars: Daniel Booko as Cort, Teresa Castillo as Ashley, Justin Prentice as Brad, Malcolm Devine as Roy, Abby Wilde as Stacey Dillsen, and Greg Mullavey as Grandad Shay
 A video of Nevel Papperman (in his first appearance since Season 2's "iFight Shelby Marx") yelling at a little girl (Caitlin Carmichael) goes viral and ruins his image, so he asks the iCarly gang for help in restoring his reputation. The iCarly gang help Nevel by posting a video of him selling smoothies to customers and creamed corn at the Groovy Smoothie. The attempt fails to restore his reputation. Nevel then chooses to sincerely apologize on iCarly to the little girl he yelled at, who surprises Nevel by appearing on the webcast (thanks to Carly and Sam) and accepting his apology. This succeeds in gaining the public's sympathy and Nevel is no longer hated. That is, until he is caught on video losing his temper with a man in a wheelchair who bumped into him. Nevel later appears in iHalfoween seeking revenge on the gang for not helping him get over the wheelchair incident.
 Ridgeway High School is holding a lock-in during which students pull all-nighters and work on finishing projects. After learning that Cort has been fired, Brad is hired as an intern for iCarly. He and Freddie team up for their school project, which is a mood reader application for the PearPad called Mood Face. To everyone's surprise, Sam volunteers to work with them on their project, and they accept her help. Sam then uncharacteristically chooses to hang out with Freddie and Brad often. Spencer agrees to help Carly and Gibby with their project, which includes performing psychological experiments, by being their test subject. At the lock-in, Freddie becomes suspicious of Sam's nice behavior towards him and Brad. When he tests his Mood Face app on Sam, the results say she is in love and Freddie immediately assumes that Brad is the object of Sam's affection. He runs to tell Carly the news, which leads Carly to confront Sam about loving Brad. Sam denies having feelings for Brad, but Carly does not believe this to be true. Taking matters into her own hands, Carly decides to set Sam and Brad up, with Freddie's help, by leaving them alone in a classroom. Afterwards, Sam angrily confronts Carly about her matchmaking attempt and insists that she does not love Brad. Carly remains unconvinced, mainly because of Sam's recent eagerness to spend time with Freddie and Brad any chance she gets. Sam leaves and goes to sit alone outside the school. Freddie goes out to where she is to talk about what has happened. Sam once again denies being in love with Brad and, frustrated—as she has to admit to herself that Freddie cannot even imagine her being in love with him and still thinks she hates him due to all the things she herself had done to him in the past years—tells Freddie to leave. However, he instead gives her advice about taking a risk with love. Halfway through Freddie giving Sam advice, Sam kisses Freddie, revealing that he is the one she is in love with, as a shocked Carly watches the scene from inside the school through a window.
 Carly is in a brand new relationship with a boy named Steven. Sam goes online to TheSlap.com and sees Steven with another girl by the name of Tori Vega and tries to inform Carly that Steven is cheating on her, but Carly refuses to believe her unless she has proof, saying "everyone is innocent until proven cheaty". The group, including Gibby, decide to drive down to Los Angeles and crash a party at Kenan Thompson's house that Andre, one of Tori's friends, is holding, via a public invite posted by Rex, the puppet of Robbie, another one of Tori's friends, to find out if Steven is really cheating on Carly. But before they arrive at the party, they get professional disguises for the party in case anyone recognizes the iCarly gang (which would cause major distractions). They stop at the house of Moni, who was Spencer's past girlfriend and is also a celebrity makeup artist. Moni, though still angry at Spencer for backing a car over her, transforms them into different looking people. When many people show up to the party and begin to party recklessly thanks to Rex's post, Andre tries to get some people to calm down and/or leave, as he thought there were only supposed to be a few people at this party, though failing, while getting chased by a mysterious man in a panda suit. Kenan arrives and is surprisingly cool with the party, claiming that there are not enough people at the party. However, he is annoyed at the panda, who has stalked him for years, and agrees to help Andre chase him off his property.
 Carly catches Steven with Tori, and she sees him giving Tori the same exact charm bracelet that he gave her and telling her, "it's one of a kind, just like you", which he also had told Carly at the beginning of the episode. Tori then tells Steven that she loves him and Steven says "I love you too" making Carly devastated. Tori finds Carly and her friends at the party, now in their normal looks, where Carly reveals that Steven is cheating with both of them. Carly and Tori, together with Sam, Freddie and Kenan, come together with a plan to expose Steven's bad nature live on iCarly in front of a million people in a small closet where Tori and Steven originally planned to have their 100-day kiss. Steven angrily leaves the closet while the iCarly gang party inside.
 The whole time this is happening, other events occur, including Spencer with Jade and Beck, friends of Tori, and one of Tori's teachers, Mr. Sikowitz, having an awkward encounter in a hot tub, Trina, Tori's sister, having trouble babysitting two younger children for a friend while attending the party, and Rex having a freestyle rap battle with random people in the audience, though eventually getting beaten by Sam. The episode then closes with the casts of the two shows singing a mashup of their theme songs, "Leave It All to Shine".
 Special guest appearance by: Kenan Thompson as himself
Special guest stars: Victoria Justice as Tori Vega, Leon Thomas III as Andre Harris, Matt Bennett as Robbie Shapiro, Elizabeth Gillies as Jade West, Ariana Grande as Cat Valentine, Avan Jogia as Beck Oliver and Daniella Monet as Trina Vega
Guest stars: Eric Lange as Erwin Sikowitz, Michael Eric Reid as Sinjin Van Cleef, Mary Scheer as Mrs. Benson, Jake Farrow as Rex Powers, Cameron Stewart as Steven Carson, Kwame Patterson as DJ Mustang, David St. James as Mr. Howard, Jen Liley as Monie, Lane Napper as Lane, Marilyn Harris as Andre's Grandmother, Cierra Russel as Mabel, Walt Shoen as Wilson, Dabier as Rex Challenger, Justin Castor as Mark and BooG!e as Panda.