On her 14th birthday, Princess Star Butterfly receives a magical wand, but when she sets fire to the castle, she is sent to Earth to train. There, she enrolls in Echo Creek Academy where the principal pairs her with Marco Diaz, a reputed "safe kid". Upon befriending Marco, Star ends up discovering his skills when she is attacked by Ludo and his army of monsters. Star receives a visit from Flying Princess Pony Head, her best friend from Mewni. Pony Head is jealous that Marco is Star's best friend on Earth. She invites Star and Marco to various dance clubs, but she competes with Marco for Star's attention and tries to strand him at a video arcade. Meanwhile, guards have been hot on Pony Head's trail. Eventually, King Pony Head arrives to have the guards take Pony Head to St. Olga's Reform School for Wayward Princesses.
"Matchmaker" - In an effort to get a better grade on her math test, Star offers to help her teacher Miss Skullnick with her love life but accidentally turns her into a troll. "School Spirit" - Star, still unfamiliar with the lingo on Earth, misunderstands when she hears that the Echo Creek football team is going to "get slaughtered" and prepares a series of booby traps to protect them.
"Monster Arm" - When Marco hurts his arm before a big karate tournament, Star tries to fix it with magic but accidentally turns it into a giant tentacle. Nick Swardson ("Reno 911!") guest stars as Sensei. "The Other Exchange Student" - The Diaz family's charming former exchange student, Gustav, comes to visit and Star is convinced that he has an evil motive for returning.
"Cheer Up Star" - Star is feeling down when she doesn't get a call from her crush, Oskar, so Marco tries to cheer her up but accidentally summons Ludo and his army of new monsters. Jon Heder ("Napoleon Dynamite") guest stars as Oskar. "Quest Buy" - Star and Marco must navigate through a maze-like store, Quest Buy, to get a new wand charger before Star's wand dies forever.
"Diaz Family Vacation" - After inviting the Diazes on a trip to Mewni as a last minute anniversary present, Star and Marco must save them from a many-headed serpent. "Brittney's Party" - Star must fight off Ludo and his army of monsters when they crash Brittney Wong's birthday party.
"Mewberty" - When Star starts sprouting hearts all over her body, the telltale sign of Mewberty, Marco searches for a way to keep her from losing control. Emmy Award nominee Jeffery Tambor ("Transparent") guest stars as Glossaryck. "Pixtopia" - Marco and his friends travel to a dimension of pixies and are forced to work off their debt in the Shard Mines after they run up Star's Magic Mirror bill with prank phone calls. Anna Camp ("Pitch Perfect") guest stars as Pixie Empress.
"Lobster Claws" - When Ludo fires one of his monster minions, Lobster Claws, Marco and Star attempt to help him adjust to life on Earth. "Sleep Spells" - When Star "sleep spells," Marco tries to use psychology to cure her, but her nocturnal magic turns out to be her subconscious defenses against an interdimensional criminal trying to steal her face.
"Blood Moon Ball" - Star accepts her ex-boyfriend Tom's invitation to Demon Prom, but Marco is suspicious of Tom's intentions and crashes the prom to prevent Star from getting her heart broken again. Ryder Strong ("Boy Meets World") guest stars as Tom. "Fortune Cookies" - Marco convinces Star that fortune cookies contain magical prophecies, which leads her to dangerously believe a fake fortune provided by Ludo's new evil efficiency expert, Toffee. Michael C. Hall ("Dexter") guest stars as Toffee.
"Freeze Day" - Star accidentally freezes time with her wand and must convince Father Time to set things right. Comedian Jim Gaffigan guest stars as Father Time. "Royal Pain" - Star is delighted when her dad shows up for an unexpected visit, but he soon wears out his welcome. Jamie Kennedy ("Ghost Whisperer") guest stars as Helios.
Star must face her greatest fear and travel to St. Olga's Reform School for Wayward Princesses to bust out Flying Princess Pony Head for her birthday. *Guest starring Jessica Walter (Arrested Development") as Miss Heinous and Jodi Benson ("The little Mermaid") as Singing Teacher.
"Mewnipendance Day" - Star leads a battle reenactment as part of a Mewni Independence Day celebration with her friends on Earth. "The Banagic Incident" - Star sees a commercial for a "magical" Earth product and sets off on her own to buy it, but the mission goes south when her lack of earth knowledge gets her into serious trouble.
"Interdimensional Field Trip" - Star leads a class field trip to a museum in another dimension and puts the entire class in danger. "Marco Grows a Beard" - When Star flubs the spell used to help Marco grow a beard, the beard grows out of control and engulf the house. Michael C. Hall ("Dexter") recurs as Toffee.
When Marco is captured by Toffee and held for wand-ransom, Star enters into an unlikely alliance with Ludo and Buff Frog. *Michael C. Hall ("Dexter") recurs as Toffee.
"My New Wand!" - Star must learn how to free Marco from a magically locked closet without using her new wand. *Jeffrey Tambor ("Transparent") reprises his role as Glossaryck. "Ludo In The Wild" - When Ludo is thrown into nature, he must overcome the elements and creatures of the wilderness to survive.
"Mr. Candle Cares" - Star rebels after the school guidance counselor, Mr. Candle, insists that her future is set in stone. *Dave "Gruber" Allen ("Freaks and Geeks") guest stars as Mr. Candle and Rider Strong ("Boy Meets World") reprises his role as Star's ex-boyfriend Tom. "Red Belt" - Marco finally decides to focus on earning his red belt in karate.
"Star on Wheels" - When Marco teaches Star how to ride a bike but forgets to tell her about brakes, he teams up with Oskar and Glossaryck to save her. "Fetch" - A mysterious stray dog steals Star's wand and refuses give it back.
"Star vs. Echo Creek" - Star goes into hiding after accidentally destroying a car. *Yvette Nicole Brown ("The Odd Couple") guest stars as Brigid. "Wand to Wand" - Star and Ludo struggle to learn how to use their new wands properly.
"Starstruck" - When Star's biggest hero Mina Loveberry, a rogue magic-wielder from Mewni, loses her mojo for battle, Star attempts to help her get it back. "Camping Trip" - King Butterfly pays a surprise visit to Star during the Diaz family camping trip and brings with him his own brand of camping.
"Starsitting" - When Star and Marco are in charge of watching Buffrog's tadpoles, the duo's babysitting styles clash. "On the Job" - Buffrog has to complete an important mission in order to care for his kids.
"Goblin Dogs" - Star and her friends wait in the longest food truck line ever for the universe's best hot dog, the Goblin Dog. * Jerry Trainor ("iCarly") guest stars as Roy. "By the Book" - After an argument with Star, Glssaryk goes into hiding in a donut box. While Star and Marco try to convince him to come out of hiding, Ludo plots to capture Star.
"Game of Flags" - Star competes in the Game of Flags at the Butterfly-Johansen family reunion against her mother's orders. "Girls' Day Out" - When Star is nominated as Mayor of Detention, she must help her constituents with their various problems.
"Sleepover" - Marco sets out to impress Jackie at Star's slumber party, but a magical truth-telling game threatens to reveal too much for Star. "Gift of the Card" - Marco must use a gift card before it expires with catastrophic results.
"Friendenemies" - When Tom vies for Marco's company instead of Star's, Marco becomes suspicious. *Nick Lachey (98 Degrees) guest stars as Jason Towers. "Is Mystery" - Worried about his tadpoles' futures, Buff Frog investigates the hole in the Mewman force field.
"Hungry Larry" - Star and Marco help Mr. Diaz create the scariest Haunted House on the block. *Billy West guest stars as Hungry Larry. "Spider with a Top Hat" - Star's most entertaining spell, Spider with a Top Hat, wants to become a fighting spell instead. *Guest starring Steve Little as Spider, Eric Christian Olson as Rock, Ron Lynch as Narwahl Husband and Maria Bamford as Make-up Blast. TV-Y7
"Into the Wand" - Star travels into her wand to try and fix it. "Pizza Thing" - When Marco and Ponyhead pick up a pizza for Star, the simple task becomes a disaster.
"Page Turner" - Star tries to resist the temptation of reading a forbidden chapter in her Book of Spells. "Naysaya" - Marco grows a second head that blurts out his secrets and insecurities whenever he tries to ask out Jackie.
Star has second thoughts about attending a dead clown's séance, when Jackie asks Marco to go to the school dance with him.
Star tries to rescue Glossaryck and the Book of Spells from Ludo. Star sets out to prove that party magician Preston Change-O is a real magician. *Al Yankovic guest stars as Preston Change-O.
Star must show her fairy godmother, Baby, what she has learned about magic. *Melissa Rauch ("The Big Bang Theory") guest stars as Baby. When Marco abuses the Dimensional Scissors, the Scissors Enforcer, Heckapoo gives Marco an ultimatum. *Zosia Mamet ("Girls") guest stars as Heckapoo.
When Star refuses to solve a problem in math class, she learns that avoiding her least favorite subject may have cosmic repercussions. *Jim Gaffigan ("The Jim Gaffigan Show") recurs as Father Time; Carl Weathers ("Rocky") guest stars as Omnitraxus Prime. When Star discovers that the Bounce Lounge is closing, she and Marco enlist their old Bounce Crew to make sure the party continues. *Constance Shulman ("Orange Is the New Black") guest stars as Milly and Dana Davis ("Franklin & Bash") recurs as Kelly.
Rhombulus is convinced that Star is the source of a universe-wide magical glitch and brings them before the Chancellor of the Magical High Commission. Ludo forces Glossaryck to teach him about the Book of Spells.
Ms. Heinous shows up at the Diaz house and Marco must make amends for all the terrible things he has done. Marco wants to prove to Sensei that he's more worthy than Jeremy.
Star must restore Echo Creek High's spirit after destroying the Possum statue. When Star invites Jackie to a Love Sentence concert with her and Marco, she tries to make sure Jackie doesn't feel like a third wheel. *Nick Lachey (98 Degrees) guest stars as Justin Towers.
On Star's Song Day, Star and Marco work with principle songstrel Ruberiot to create a ballad for the event. *Patrick Stump ("Fall Out Boy") guest stars as Ruberiot.
Hoping to help her forget about her strained friendship with Marco, Star's friends convince her to ditch the Diaz' end-of-the-school-year party for a more dangerous bash.
Star returns to her home dimension of Mewni where she discovers that magic is disappearing throughout the kingdom. She must dig deep and challenge archnemesis Ludo in an effort to save her family and kingdom. Queen Moon shares her story of when she was a teenager and her mother (Star's grandmother) had died. She had to decide between signing a peace treaty or going to war against the monster army, led by "The Lizard". She partly melts the ice encasing Eclipsa, to learn some dark magic from the forbidden section of the Book of Spells. She confronts The Lizard (Toffee) and uses the dark magic to sever his finger, which he is unable to regenerate. Toffee flees.
Despite dire warnings, Ludo tries to write a new chapter in the Book of Spells. King River cannot keep up the kingdom without Queen Moon.
Buffrog helps Star escape from Moon's ever-protective watch. With Ludo in control of the kingdom, Marco must decide his next move.
King Ludo's reign reaches as a tipping point as Star returns to the castle. Star must summon her strength to save her family and the kingdom.
"Scent of a Hoodie" - Star goes to the Royal Laundry, and meets the Knight of the Wash. "Rest in Pudding" - Star continues to have recurring visions of Glossaryck and believe he is haunting her.
"Club Snubbed" - Tom snubs Star at the Silver Bell Ball. *Rider Strong ("Boy Meets World") recurs as Tom. "Stranger Danger" - Star meets the ancient Queen Eclipsa. *Esmé Bianco ("Game of Thrones") recurs as Queen Eclipsa.
"Demoncism" - Star and Tom's friendship is put to the test when Tom decides to get rid of his demons. *Rider Strong ("Boy Meets World") recurs as Tom. "Sophomore Slump" - Marco decides to put in a full effort to living life in the present on Earth.
"Lint Catcher" - Knight of the wash, Sir Lavabo, gets a familiar squire. "Trial by Squire" - Star prepares for the Midnight Warrior Blowout Sale at Quest Buy.
A surprise visitor pressures Marco to reveal Turdina's true identity. Star goes out into the field to understand why Mewmans treat Monsters unfairly.
Star discovers she travels through multiple dimensions in her dreams. Kelly breaks up with her boyfriend and Marco questions his friendship with Star Butterfly.
Star urges the royal youth of Mewni to sign a petition calling for the equal treatment of Monsters. Star is thrilled when Ponyhead invites her to dinner with her sisters.
Star learns that Marco and Hekapoo have been dealing with rogue interdimensional portals. Star's sleep-portaling becomes a danger and she decides to put a stop to it.
All the youth of Mewni gather at the ancient Monster Temple to celebrate a new era of Monsters and Mewmans living together in peace, until guests start disappearing!
"Stump Day" - Star, Marco and the rest of Mewni celebrate a special snowy holiday, "Stump Day." "Holiday Spellcial" - Spider with a Top Hat invites one of Eclipsa's dark spells to the office holiday party.
"The Bogbeast of Boggabah" - King River interrupts Star's eager investigation into Eclipsa's past and demands her help on a dangerous hunt. "Total Eclipsa the Moon" - Moon enlists Ecplisa herself to access Mewni's most guarded records.
Moon and the Magical High Commission put Eclipsa on trial for her evil past with Star as a key witness. Dennis goes on a dangerous journey to find Ludo living in another dimension.
Buffrog leaves Mewni in search for a better life, and Star goes to look for him. Marco returns to Echo Creek to discover that his mom is pregnant.
Ponyhead returns to St. O’s and finds that the curriculum got tougher. A magical photo booth at a wedding goes on the fritz and captures Star and Marco inside
Pony Head shuts herself away to watch the finale of her favorite Korean drama. Eclipsa and Moon bring Princess Meteora home peacefully after the massive destruction she's caused.
Star becomes acting Queen and plans for Marco and his warriors to delay Meteora from reaching Castle Butterfly long enough for Star to find Moon and destroy the monster princess.
Star must find the courage to face Meteora alone and make a decision that will change the kingdom forever.