Season 3 was announced on February 9, 2016. It premiered on January 7, 2017. It ended on August 5, 2017.
In this season, the Harper Quads face a new set of quadruplets, the adorable Kramden Quads. Unlike the Harpers who have nothing in common, the Kramdens have everything in common, look alike and work in harmony. The Harper Quads also undergo major growths this season with graduation from Edgewood School and Dawn and Dicky going through puberty. The quads also make new friends including Miles, Dooley and Avery.
On several occasions this season, the quads are forced to face reality about their reputation that they are selfish and have the tendency to ruin things they're involved with.
- Lizzy Greene as Dawn Harper (24/24 Episodes)
- Casey Simpson as Ricky Harper (24/24 Episodes)
- Mace Coronel as Dicky Harper (24/24 Episodes)
- Aidan Gallagher as Nicky Harper (24/24 Episodes)
- Allison Munn as Anne Harper (24/24 Episodes)
- Brian Stepanek as Tom Harper (24/24 Episodes)
- Kyla Drew Simmons as Mae Valentine (23/24 Episodes)
- Theodore Barnes as Miles (13/24 Episodes)
- Siena Agudong as Natlee (11/24 Episodes)
- Hayden Crawford as Dooley (8/24 Episodes)
- Isabella Revel as Avery (6/24 Episodes)
- Jason Sims-Prewitt as Principal Tarian (5/24 Episodes)
- Gage Petrone as Franco (4/24 Episodes)
- Madison Hubbard as Emma Kramden (4/24 Episodes)
- Savannah Hubbard as Jules Kramden (4/24 Episodes)
- Ethan Kent as George Kramden (4/24 Episodes)
- Gavin Kent as Lyle Kramden (4/24 Episodes)
- Spencer Tomich as Trey (3/24 Episodes)
- Sofia Wylie as June (3/24 Episodes)
- Molly Jackson as Brianna (2/24 Episodes)
- Jessica Belkin as Madison (1/24 Episodes)
- Lydia Boland as Molly (1/24 Episodes)
- Lincoln Melcher as Mack (1/24 Episodes)
- Mackenzie Ziegler as Lilly (1/24 Episodes)
- Maddie Ziegler as Eiffel (1/24 Episodes)
Special Guest Cast
- Alex Shibutani as Himself (Quad With a Blog)
- Maia Shibutani as Herself (Quad With a Blog)
- Breanna Yde as Simone (To Be Invited or Not to Be)
- Riccardo Hurtado as Joey Montagelli (Not-So-Sweet Charity)
- Audrey Whitby as Tori (One Quadzy Summer)
- Noah Urrea as Dylan (One Quadzy Summer)
- Buddey Handleson as Wally (Quadpendence Day)
- Jade Pettyjohn as Rose Durkin/Dorothy (The Wonderful Wizard of Quads)
- Gabby Douglas as Twisty (The Wonderful Wizard of Quads)
- Dana Snyder as Dr. Colosso (The Wonderful Wizard of Quads)
- Tia Mowry as Erica Knightly/Witch (The Wonderful Wizard of Quads)
- 01/07/17 - Quad With a Blog (301)
- 01/14/17 - Odd Quad Out (302)
- 01/21/17 - Keeping Up With the Quadashians (303)
- 01/28/17 - The Great Mullet Caper (304)
- 02/04/17 - Quadsled (305)
- 02/11/17 - Ye Olde Hand Holde (309)
- 03/18/17 - What's the Worst That Quad Happen? (310)
- 03/25/17 - To Be Invited or Not to Be (313)
- 04/08/17 - Ele-Funk in the Room (307)
- 04/15/17 - Tween Wolf (308)
- 04/22/17 - This Little Piggy Went to the Harpers (306)
- 04/29/17 - I Want My Mae B. Back (311)
- 05/06/17 - The Buffa-Lowdown (314)
- 05/13/17 - Quadshank Redemption (320)
- 05/20/17 - Not-So-Sweet Charity (318)
- 06/03/17 - One Quadzy Summer (319)
- 06/10/17 - Quad for Teacher (316)
- 06/17/17 - Quadpendence Day (315)
- 07/08/17 - Cementing the Quads' Legacy (323)
- 07/15/17 - QUADGOALS (312)
- 07/22/17 - A Space Quadyssey (317)
- 07/29/17 - YOCO (324)
- 08/05/17 - The Wonderful Wizard of Quads (321-322)
- This season had previews of episodes from September 2016 to November 2016 that later premiered in January 2017.
- The theme song completely revamped this season.
- The executive producer and creator, Matt Fleckenstein, left the show before production begun for this season leaving Michael Feldman in charge of the show.
- Kyla Drew Simmons, who portrays Mae Valentine, was promoted to a main character. Although, she is absent in the episode, YOCO.
- Mace Coronel's haircut changes to medium-length and his voice got deeper due to his actor going through puberty between Season 2 and Season 3 production.
- This season was originally ordered for 14 episodes on February 9, 2016, by Nickelodeon, but during production later got expanded by ten episodes, making the season consist of twenty four episodes.
- Production for this season was from April 26, 2016 to February 10, 2017.
- A new café from Get Sporty is introduced in the episode, Quad With a Blog, after in that episode the old café burned down.
- The episode The Great Mullet Caper was the 50th episode produced, of the series.
- This season ended exactly one year after Season 2.
- This season only aired for eight months; as the scheduling from Season 2 pushed back the Season 3 premiere.
- Ricky Harper wears similar blue jeans to the ones he wore in Scaredy Dance in the episodes Cementing the Quads' Legacy, QUADGOALS and The Wonderful Wizard of Quads.
- New recurring characters were introduced this season. They included, Miles, Dooley, Avery, June, Kramden Quads, and Franco.
- There were so many special guest stars this season. There were many sports players and Nickelodeon stars. There were three School of Rock stars, including, Breanna Yde, Riccardo Hurtado and Jade Pettyjohn, whom appeared in the episodes, To Be Invited or Not to Be, Not-So-Sweet Charity and The Wonderful Wizard of Quads, respectively. There were also two The Thundermans stars, which were, Audrey Whitby and Dana Snyder, whom appeared in One Quadzy Summer and The Wonderful Wizard of Quads, respectively. They had a couple of singers, Noah Urrea and Gabby Douglas. They had a pair of Ice Skaters, Maia and Alex Shibutani. Finally, they had and actor, Tia Mowry, and the former Bella and the Bulldogs star, Buddy Handleson.