In an official statement, Disney Channel's Executive Vice President Adam Bonnett said, "The strength of this series helped make 2013 Disney Channel's highest-rated year ever among tweens, an audience that is invested in the 'Austin & Ally' stories and the fun they experience on a journey with the characters. We're looking forward to delivering many more engaging stories soon." 
The writers started working again on August 18, 2014 and production for the season began on October 13, 2014.  Season 4 premiered on January 18, 2015 at 8 pm ET/PT.
After spending the summer apart, Austin, Ally, Trish and Dez are back and ready for senior year! Austin focuses on finishing school and just being a normal kid while Ally takes a break from touring to work on her next album. Trish questions her future as a manager while Dez contemplates going back to film school in L.A. But all future plans are put on hold as the gang works to open their own pop star academy to teach kids about performing and making music.
|Image||No.||Ep.||Title||Original air date||Prod.|
|68||1||"Buzzcuts & Beginnings"||January 18, 2015||401|
|The gang shares an emotional reunion in Miami at Ally’s triumphant homecoming gig. When Austin learns that the foursome’s time together is only temporary, he contemplates enrolling in military school.|
|69||2||"Mattress Stores & Music Factories"||January 25, 2015||402|
|Unable to find a new passion, Austin feels forced to take a job at his parents’ mattress store, and Ally struggles to keep up with an influx of music students. Dez and Trish try and help the duo to come up with a plan that will solve both of their problems.|
|70||3||"Grand Openings & Great Expectations"||February 8, 2015||403|
|The gang are challenged by a reporter to teach first-time music students how to play in a band in less than a week before the big grand opening of the A&A Music Factory. Looks like Austin, Ally, Trish and Dez are going to need some help...|
|71||4||"Seniors & Señors"||February 15, 2015||404|
|The foursome’s plans to enjoy their senior year together are put on hold when Austin learns that he’s a credit short and still a junior in high school. Thankfully, his friends are always there to help and Trish even gets a Marachi singer to sing every word in Spanish that Austin says in English.|
|72||5||"Homework & Hidden Talents"||March 28, 2015||405|
|Ally makes a bet with Austin to prove that she can unlock the hidden musical talent of a new student. Meanwhile, Trish is not exactly happy with the way Dez is helping her with her homework.|
|73||6||"Duos & Deception"||April 19, 2015||409|
|Trish books Billie and Bobbie of “The Billie and Bobbie Show,” a famous brother and sister duo, to talk and perform with the students of the A&A Music Factory. Meanwhile, when a code inspector comes to look at the music school and threatens to shut it down, Ally, Austin, Trish and Dez learn the famous duo have ulterior motives.|
|74||7||"Wedding Bells & Wacky Birds"||May 3, 2015||406|
|When Austin and Ally are paired together in Home Ec, they get to imagine life together as a married couple. Meanwhile, Trish helps Dezbook a job directing a commercial...which just happens to star his ex-girlfriend Carrie.|
|75||8||"Karaoke & Kalamity"||June 14, 2015||412|
|Desperate to perform again, Austin begins singing at a karaoke club in disguise — as a lumberjack! Meanwhile, back at the A&A Music Factory, Ally mentors a student with stage fright.|
|76||9||"Mini-Me's & Muffin Baskets"||June 21, 2015||413|
|As the team prepares for the A&A Music Factory’s first showcase, Austin pulls out all the stops and wants to surprise Ally by teaching their students one of her songs. But, Trish’s new student, Sadie, threatens and somehow manages to mess everything up.|
|77||10||"Dancers & Ditzes"||July 12, 2015||407|
|Ally is performing at an awards show but the producers...and her friends are worried about her dancing abilities.|
|78||11||"Mysteries & Meddling Kids"||July 26, 2015||417|
|A mystery unfurls when Ally’s songbook is stolen from the school’s ’70s-themed party. What better way to catch the culprit than channeling the Mystery Bunch gang that Austin, Trish, and Dez dressed up as to solve the crime?!|
|79||12||"Comebacks & Crystal Balls"||August 9, 2015||408|
|A visit with a fortune teller convinces Austin that something bad will happen during his comeback concert — and with Dez’s help, it kind of does — he gets stuck inside a box! Meanwhile, Trish believes she is going to meet a prince.|
|80||13||"Burdens & Boynado"||August 23, 2015||418|
|When Trish’s boy-band client Boynado threatens to split up, she searches to find a way to fix their problems. And the answer may rely in a wannabe singer. Meanwhile, Austin and Ally try to help a former impersonator find his own voice.|
|81||14||"Bad Seeds & Bad Dates"||September 20, 2015||411|
|Ally learns that the new woman her dad is seeing a new woman. Unfortunately, she just also happens to be the mom of a very difficult student at the A&A Music Factory.|
|82||15||"Scary Spirits & Spooky Stories"||October 4, 2015||414|
|While visiting New York, the group attends the Central Park Spooktacular party, which inspires them to tell their own scary stories — plus it helps that there’s a contest!|
|83||16||"Rejection & Rocketships"||November 8, 2015||415|
|When Ally is rejected from her number one college, she decides to let go of her “perfect student” ways. Meanwhile, Austin and Dez discover their favorite childhood ride will shut down forever.|
|84||17||"Cap and Gown & Can't Be Found"||November 22, 2015||416|
|When a missing library book threatens to keep Ally from graduating, Austin tries to find it. Meanwhile, Trish fakes some memorable moments in an attempt to get more photos in the yearbook, with a little help from Dez.|
|85||18||"Santas & Surprises"||December 6, 2015||410|
|When one of Austin and Ally’s music students, Lily, is sad about spending Christmas away from her father, the gang rallies around her to try and make her happy. Meanwhile, Dez and Trish take jobs as Santa’s helpers at Miami Mall.|
|86||19||"Musicals & Moving On"||January 10, 2016||420|
|As the rest of the group prepares for the next phase of their lives, Trish is still determining what her next steps will be.|
|87||20||"Duets & Destiny"||January 10, 2016||419|
|Years after the gang has gone their separate ways, Ally, Austin, Trish and Dez meet-up and learn what they have all been up to, individually.|
- Ross Lynch as Austin Moon
- Laura Marano as Ally Dawson
- Raini Rodriguez as Trish De la Rosa
- Calum Worthy as Dez Wade
- This season makes Austin & Ally the 6th Disney Channel series in Disney Channel history to make it to Season 4 and the 4th live-action series to make it to Season 4 (preceded by That's So Raven, Hannah Montana, Phineas and Ferb, Wizards of Waverly Place, and Good Luck Charlie).
- This season also makes Austin & Ally the first Disney Channel series with a four-member cast, main characters who are not a family and a male co-lead to receive a fourth season.
- There is a new set replacing Sonic Boom this season, the Austin & Ally Music Factory.
- This season includes special guest stars, such as Maddie Ziegler (Dance Moms), Becky G, Skylar Stecker, Leslie David Baker (The Office), Dove Cameron and Ryan McCartan (Liv and Maddie), and Kamil McFadden and Trinity Stokes (K.C. Undercover).
- This season introduces a new version of the Can't Do It Without You intro sequence, featuring the cast as they appear now and clips from episodes in Seasons 2 and 3 (much like most other Disney Channel shows have, such as JESSIE, Girl Meets World, and K.C. Undercover). Additionally, it now features Laura Marano singing alongside Ross Lynch.
- In a TVLine interview with Laura Marano, it stated that the series finale would air in early 2016.
- An EP, titled Austin & Ally: Take It From The Top, was released featuring five of the songs that will be sung by Laura Marano and Ross Lynch in the season.
- The cast had their final table read of Austin & Ally on April 13, 2015.
- Production wrapped up for the season and Austin & Ally on Thursday, April 23, 2015.
- The season premiere was "Buzzcuts & Beginnings".
- Laura revealed the last song of the series/season will be a duet.
- This is the final season of the show.
- During an interview, Raini said that the series finale will be sad with lots of crying and that there will be a lot of "feels", which hints that there might be a big Auslly moment in the series finale.
- This season has 20 episodes.
- The writers revealed on twitter that Ally's middle name will be revealed in the season.
- Austin & Ally was crossing over with K.C Undercover, as part of Monstober 2015, but only Ernie (Kamil McFaddin) and Judy (Trinitee Stokes) made an appearance. Also, there was another crossover with I Didn't Do It, where only Logan Watson (Austin North) and Delia Delfano (Sarah Gilman) made an appearance.
- "Seniors & Señors" didn't air in Latin America (except Brazil) due to the plot not making sense with all of the characters constantly speaking Spanish.
- On December 2, 2015, it was exactly 4 years since Austin & Ally debuted on Disney Channel.
- The season (and series) finale is "Duets & Destiny" and aired on January 10, 2016, along with the penultimate episode of the series, "Musicals & Moving On".
- On January 2nd there was a takeover on Disney Channel, with episodes and outtakes.
- There were 2 takeovers this season. The first aired January 10, 2015 - January 12, 2015 for Seasons 1-3 leading up to the Season 4 premiere while the second aired January 2, 2016 - January 4, 2016 for the entire series leading up to the series finale.
- Austin & Ally ended with a total of 87 aired episodes and 4 crossovers (Jessie, K.C. Undercover, I Didn't Do It, and Girl Meets World).
- In Part 1 of the series finale, Ally gives Austin her songbook, with Austin proposing to Ally, ending with a cliffhanger which continues in Part 2.
- In Part 2, which is an epilogue, Austin & Ally broke up for 4 years. They perform back on the Helen Show "Two In a Million" in 4 years.
- The series also ended with Austin & Ally married with 2 kids, Trish married to Chuck with 1 daughter who has the character traits of Trish, and Dez married to Carrie. This is notable for being the first Disney Channel show whose main characters get married.
- The final words of the series were said by Ally, "Remember this one?"
- The last scene of the series was with Austin & Ally sitting in the practice room at their old piano playing the melody to Can't Do It Without You, the series theme song.
- The finale aired in February half term in the UK.
- This season also makes Austin & Ally the third Disney Channel Original Series to alter its theme song for Season 4, preceded by Wizards of Waverly Place and Hannah Montana.
- This season, out of all the Disney Channel Original Series with a fourth season, is the first to keep its original opening but add clips, making Austin & Ally Season 4 to have a typical and clip opening altogether.
- Raini's Tweet About Her Excitement for Season 4
- Laura reveals air date of the series finale
- An Evening with the Cast and Creators of Austin and Ally