Jessie accepts a job as a nanny and moves in with the Ross family, high-flying couple Christina, a former supermodel turned business mogul, and Morgan, a famous movie director, their four kids Emma, Ravi, Luke and Zuri and their beloved 7-foot Asian Water Monitor Lizard. Nanny responsibilities are more difficult than Jessie anticipated as she coaches Emma, who is on the brink of a science fair meltdown.

Despite being weary of Ravi's seven-foot Asian Water Monitor Lizard, Mr. Kipling, Jessie comes to the lizard's rescue after the head of the condo board attempts to ban Mr. Kipling from the building. Meanwhile, Zuri brings home an another imaginary friend, and Luke and Emma compete against each other in a school photography class.

After Jessie accepts an invitation for lunch with Tony, the building's doorman, Emma offers Jessie unsolicited dating advice she has learned from her stash of teen magazines. Meanwhile, Ravi becomes the target of Luke's practical jokes.

After Jessie embarrasses Luke in front of a bully, he doesn't want her to help him with anything in public. When the mean kid faces off with Luke in the neighborhood paintball contest, Luke has no one to be his partner. Upset, Jessie arrives at the park to prove to Luke that she can help him win the paintball war. Meanwhile, Zuri invites Emma to her tea party, but Emma turns down the invitation when her friend Jasmine gives her a free pass to a fashion show. Zuri invites Bertram instead but doesn't think he's a very good guest during the party, which upsets her. On the day of the fashion show, Jasmine un-invites Emma, so Emma decides to attend her Zuri's tea party to cheer her up. Jessie helps Luke win the paintball competition.

After a music producer spots Jessie and Luke performing in the park, he promises them fame and gets them to his studio to shoot a music video. However, Jessie and Luke fight over the spotlight, causing problems. Meanwhile, Bertram enlists Emma to help style him for his social network profile photo, and Zuri and Ravi take Tony's place at the reception desk to prove to Tony that his job is not as hard as he makes it seem. When Tony finds out about Jessie and Luke, he warns them that the "manager" is a fraud who fools people for their money. Jessie and Luke resolve their problems and abandon the manager, and Tony shoots a new music video for Jessie's song with Jessie and all of the children starring in it.

Jessie gets worried that Zuri may have imaginary friends her whole life, so she tries to find her an actual friend at the park. Zuri meets Nana Banana, a former clown with a colorful personality, but Zuri begins to favor Nana Banana over Jessie. Jealous, Jessie throws Nana Banana out after a banana peel is left on the stairs, which upsets Zuri. Meanwhile, Mr. Kipling falls in love with a plastic toy animal at the park, so Luke, Emma and Ravi rob it from the park, while trying to avoid Ranger Bill, the park security guard. When they accidentally break the toy and try to return it to the park, they are caught. However, Nana Banana saves them from getting in trouble, which makes Jessie realize her mistake and apologize to Nana Banana, leading to all of them becoming friends.

Jessie believes Connie, a math tutor she finds for Luke, will be the perfect scholarly influence, not realizing Connie is obsessed with Luke. Connie asks Luke to a Harry Potter dance, and Jessie forces him to accept. Jessie soon realizes that Connie really is a creepy stalker and tries steering her away from Luke. In turn, Connie steals Luke's beloved stuffed animal, Kenny the Koala, in order to make Luke go to the dance. Once Jessie tells her that Luke has read none of the Harry Potter books, Connie, horrified, declares her love for Luke dead, and leaves. Meanwhile, Ravi is convinced that he can predict the future with his Mystical Eye-ball Application on his tablet.

Jessie and Bertram are left in charge of bringing the Christmas spirit to Ravi, Emma, Luke, and Zuri. Lukes wants to kiss Jessie under the mistletoe. At the toy store, Jessie, Emma & Luke get caught in Toy Jail. But when their parents are stranded because of a blizzard, things go wrong. Zuri tells Ravi about Santa and Ravi gets petrified by him. The parents make it home for Christmas and Luke quickly kisses Jessie.

A celebrity comes to the Ross household. Emma and Jessie fight for his affection,while Zuri and Luke make prank phone calls. The star asks Jessie out but Emma ruins it. Bertram pretends to work while Mr.Ross is in town.

After Zuri's doll is ruined, Zuri and Jessie attempt to raise two hundred dollars for a new one. Meanwhile, Ravi starts as the new kid in the same school with Luke and Emma, but embarrasses Luke after trying to fit in. However, when Ravi defeats the school bully with his traditional Indian Dragon Fire Peppers, everybody praises him, and Luke and Ravi resolve their problems. Jessie helps Emma with a heel problem.

Jessie and Zuri go on a train ride. Emma and Ravi get left at the station. Bertram and Luke hunt a spider.

Jessie and Zuri were making a video to send to Jessie's old friend, so Zuri took Christina Ross's tiara so Jessie can wear it. Jessie accidentally knocks the tiara off her head and over the ledge, where it lands in Mrs. Chesterfield's hot tub. When Mrs. Chesterfield refuses to return the tiara, Jessie and Zuri convince Bertram to ask Mrs. Chesterfield on a date so they can take it from her apartment. Meanwhile, Ravi, Emma and Luke all see a video online and have an idea to make Mr. Kipling a star. The title is a send-up of the film title Romancing the Stone.

Normally, Jessie reads Zuri a bedtime story, but this time Zuri reads the story, which soon places all of them into a medieval world. Tony will do anything to please one of the princesses, which is Jessie, but there is another guy fighting for her, who is supposed to represent a guy named Brody in the real world. In the real world, a guy named Brody asks Jessie out on a date, which actually causes Tony to become jealous, just like in the medieval story. Both of the boys go on a great medieval "adventure" in the story to try to get Jessie to be their princess. They joust for Jessie, but Tony is obviously weaker than Brody. Besides the medieval storyline, Tony is conflicted about Jessie and Brody going on a date together. In the real world, Jessie finds out Brody also has another girlfriend and decides not to go on a date with him. Tony asks Jessie out on a date and she accepts.

Jessie competes with another nanny named Agatha who forbids her from taking the Ross kids to Central Park. She ends up putting pictures of Jessie online that makes her look like a bad nanny.

Jessie thinks Luke needs strict discipline to keep him from misbehaving and enlists the help of fellow nanny, Samantha, who winds up being a dog nanny. Meanwhile, the kids break into Bertram’s cluttered room and Jessie makes them help clean it up after all of it fell and turned into a huge pile of Bertram's things which Ravi gets stuck in.

Jessie is tasked with ungluing Mrs. Chesterfield's hands from her head, while Ravi attempts to uncover who switched Mrs. Chesterfield's hair gel with stay stick glue. Meanwhile, Tony and Jessie plan a fun date.

Jessie has her hands full trying to keep a watchful eye on Emma, who has a major crush on bad boy with a bad reputation, Vincent. Meanwhile, Zuri becomes too protective of her favorite tree in Central Park.

Zuri enters the Little Miss Big Apple Competition against Lindsey, a kid who Agatha's watching. But when Jessie finds out that Zuri has no talent,she insists that Zuri lip sing. When Zuri plans to cheat on her schoolwork, Jessie apologizes for teaching her that cheating seems right. Zuri ends up doing an acting scene,but her and Lindsey don't win.

Nanny Agatha’s twin sister, Angela, is in town and Jessie suspects she is trying to steal her job and also catch Tony’s eye. Meanwhile, Emma copes with a giant zit on her nose.

Emma and Zuri plan a romantic mystery-filled fifth first date for Jessie and Tony. Meanwhile, Ravi, Cameron and Bertram get stuck in a giant teacup on a billboard, after their failed attempt to rescue Ravi's toy helicopter.

After the girls watch a scary movie, Jessie tries to help Zuri conquer her fear of dolls by confessing her own fear of porta-potties. Meanwhile, Cameron teaches Ravi how to impress a girl and Bertram listens to opera non-stop to win a radio contest.

Jessie, Bertram and the kids head to Bali for a family vacation, but when their private jet starts to experience difficulties, Jessie takes control of the cockpit and makes an emergency landing on a tropical island. Jessie must figure out how to get the kids home safely, all while recovering from poisonous bug bites, escaping scary monsters and tracking down Mr. Kipling.

Jessie directs a play she's written and casts Luke as the male lead; the play is a love story, and 'Creepy Connie' is the female lead. Meanwhile, Zuri job-shadows Bertram for her school report.

Jessie decides to pursue acting, so she auditions for a TV show.

While the Ross Family has their traditional "Gotcha Day", Jessie is left in charge to help celebrate the time when Zuri was first welcomed home in New York City. When Ravi tells the story when he first arrived in the United States, he tells Jessie that they thought Mr. Kipling was supposed to be a baby because his room was decorated as a nursery. Jessie accidently blurts out that Morgan and Christina were probably expecting a baby. Ravi gets incredibly upset; Christina gets infuriated with Jessie. The huge reveal almost ruins "Gotcha Day". Later on, Morgan and Christina tells them that his birth certificate had a typo and instead of Ravi being born in the year 2001, it said 2011, so that is why the Ross' were expecting a baby. In the end, Ravi forgives Morgan and Christina, and they give Zuri a zebra as a "Gotcha Day" present.