Season 4 of Nicky, Ricky, Dicky & Dawn was announced on March 20, 2017 by Deadline. Production began on May 9, 2017, and wrapped on September 20, 2017. The season premiered on January 6, 2018 and then aired the series finale on August 4, 2018.
On October 4, 2017, both Nickelodeon and Mace Coronel announced that they had mutually parted ways for Mace to leave the show before they had completed filming the season. Therefore, Dicky Harper, missed the final five episodes of the series. His final appearance was Quadbusters.
On November 6, 2017, Lizzy Greene revealed to fans that a new character named Britt would replace Dicky. Dicky was said to have taken a little trip to Australia and was therefore replaced by Britt. He is portrayed by Jonah Hwang.
On December 23, 2017, promos of episodes in Season 4 were started to be shown, these episodes were included; Dude, Where's My School?, Wrestle-Mae-nia, Nicky, Ricky, Dicky & BeyDawncé, The Harper Quad-Jobbers, Quadentity Crisis, and Quadbusters.
- Lizzy Greene as Dawn Harper (14/14 Episodes)
- Casey Simpson as Ricky Harper (14/14 Episodes)
- Mace Coronel as Dicky Harper (9/14 Episodes)
- Aidan Gallagher as Nicky Harper (14/14 Episodes)
- Allison Munn as Anne Harper (14/14 Episodes)
- Brian Stepanek as Tom Harper (14/14 Episodes)
- Kyla Drew Simmons as Mae Valentine (13/14 Episodes)
- Jonah Hwang as Britt (3/14 Episodes)
- Theodore Barnes as Miles
- Ariana Molkara as Sadie
- Sidney Floyd as Brooklyn
- Hayden Crawford as Dooley
- Isabella Revel as Avery
- Miles Elliot as Kipper
- Rena Strober as Ms. Tassinari
- Rose Abdoo as Principal Sarah Noonan
- Siena Agudong as Natlee
- Lydia Boland as Molly
- Lincoln Melcher as Mack
- Mackenzie Ziegler as Lilly
- Michael Goodman as Cash
- Maddox Henry as Zayn
- Paul Vogt as Mr. Wigglesworth
- Gabrielle Sanalitro as Gladys
- Tessa Bella as Taylie
Special Guest Cast
- Daniella Perkins as Jade
- Ricky Garcia as Zeus
- Isaiah Thomas as Himself
- James Thomas as Himself
- Jaiden Thomas as Himself
- Buddy Handleson as Wally
- 01/06/18 - Dude, Where's My School? (401)
- 01/13/18 - Wrestle-Mae-nia (407)
- 01/20/18 - Nicky, Ricky, Dicky & BeyDawncé (402)
- 01/27/18 - It's a Hard Knocks Life (403)
- 02/03/18 - Sympathy for the Squishy (404)
- 02/17/18 - The Harper Quad-Jobbers (406)
- 06/02/18 - Leader of the Stack (405)
- 06/09/18 - Quadentity Crisis (408)
- 06/23/18 - Quadbusters (409)
- 06/30/18 - Quadcodile Dundee (411)
- 07/14/18 - House Crushing for Dummies (412)
- 07/28/18 - We'll Always Have Parasites (410)
- 08/04/18 - Quadspiracy Theory (413)
- 08/04/18 - Lasties with Firsties (414)
- Season 4 is a short-length season with consisting of only fourteen episodes.
- The season is more modern-day than the three other seasons. Similar to The Thundermans.
- Mace Coronel have mutually parted ways with Nickelodeon before leaving the show in August 2017.
- On Instagram, Kyla Drew Simmons, Allison Munn and Aidan Gallagher gave hints to it being the last season, with their posts and also stating that Nickelodeon does normally end a show after the show’s fourth season.
- Brian Stepanek is the director of the episode, Quadbusters.
- Many male characters, including Aidan Gallagher, Casey Simpson, Mace Coronel, Hayden Crawford and Theodore Barnes's voices are deeper, due to them going through puberty.
- Principal Tarian did not appear in this season, since he is the principal of Edgewood School; which the Harper Quads left. Another reason why he did not appear in this season, is due to the fact that he was filming as "The King" on the Nickelodeon live-action series, Knight Squad.
- There were six new recurring characters this season, including, Kipper, Sadie, Brooklyn, Ms. Tassinari, Britt and Principal Sarah Noonan.
- Buddy Handleson made his second guest appearance as a different character in We'll Always Have Parasites.
- After four seasons, consisting of 84 episodes, Nickelodeon announced that along with the other live action series, School of Rock, this would be their final season.
- This season had the lowest average number of viewers throughout the entire series.