Season 4 (Andre132)
March 18, 2015
August 12, 2015
The show is renewed a fourth season. The first episode is aired on March 18, 2015. The last episode is aired on August 12, 2015.
- Bionic Rebellion (401/402) - March 18, 2015
- Left Behind (403) - March 25, 2015
- Mission Mania (404) - April 1, 2015
- Spike vs. Spikette (405) - April 8, 2015
- Forbidden Hero (406) - April 15, 2015
- My Master is My Student (407) - April 22, 2015
- Mighty Rats (408) - April 29, 2015
- Bionic Action Heroes (409/410) - May 6, 2015
- Bionic Dog (411) - May 13, 2015
- Ultimate Tailgate Challenge (412) - May 20, 2015
- Space Elevator (413) - May 27, 2015
- Bionic Lair Training (414) - June 3, 2015
- New Soldiers, Old Faces (415) - June 10, 2015
- We Learn Bionics, Not Languages (416) - June 17, 2015
- Too Many Kids (417) - June 24, 2015
- Chase: The Dream (418) - July 1, 2015
- Powers and Bionics (419) - July 8, 2015
- An Unusual Amount of Missions (420) - July 15, 2015
- Bionics in Chips (421) - July 22, 2015
- Leo Leaves the Lair (422) - July 29, 2015
- Party in a Lair (423) - August 5, 2015
- Soldiers, Attack (424/425) - August 12, 2015
Main Cast Edit
- Billy Unger as Chase Davenport/Spike Davenport (22/22)
- Spencer Boldman as Adam Davenport (22/22)
- Kelli Berglund as Bree Davenport/Bree Krane (22/22)
- Tyrel Jackson Williams as Leo Dooley/Parallel Leo Dooley (22/22)
- Hal Sparks as Donald Davenport/Parallel Donald Davenport (20/22)
Recurring Cast Edit
- Maile Flanagan as Terry Perry (14/22)
- Angel Parker as Tasha Davenport/Parallel Tasha Dooley (9/22)
- Jeremy Kent Jackson as Douglas Davenport/Bob Krane (15/22)
- Will Forte as Eddy (4/22)
- Madison Pettis as Janelle Brown/Janelle Dooley (3/22)
- Cole Ewing as Sebastian Krane (14/22)
- Max Charles as Spin Krane (20/22)
- Brandon Salgado-Telis as Bob Krane/Douglas Davenport (17/22)
- Skai Jackson as Mary Krane (7/22)
- Graham Shiels as Victor Krane/Parallel Victor Krane (3/22)
- Michaela Carrozzo as Caitlin Crat (6/22)
- Mateus Ward as Marcus Davenport (11/22)
- Eddie Perino as Trent (1/22)
- John Eric Bentley as Mr. President (2/22)
- Dustin Ingram as Scott (2/22)
- Ashley Argota as S-1/Sarah Krane/Spikette Krane/Sarah Davenport (12/22)
- Telma Hopkins as Rose (2/22)
- Ben Stillwell as Owen (1/22)
- Ben Bode as Special Agent Graham (3/22)
- Garrett Backstrom as Ethan (1/22)
- Oana Gregory as Stephanie Princess (3/22)
- Grace Kaufman as Kerry Perry (1/22)
- Nicole Pettis as Agent Reed (5/22)
- Ashlee Fuss as Sabrina/Sabrina Davenport (2/22)
- Leo Howard as Troy Crat (3/22)
- Lori Alan as Edie (1/22)
Guest Cast Edit
- Bella Thorne as News Reporter
- Piper Curda as Cheerleader
- Mick the Dog as Deo
- Kamil McFadden as Rick Laps
- Russ Marchand as News Guy
- Eric Allen Kramer as Davenport Team Soldier
- Andre Antunes as Brebastian Krane
- Leigh-Allyn Baker as Mrs. Crat
- Ben Savage as Criminal
- Aedin Mincks as Mailman
Special Guest Cast Edit
- Bradley Steven Perry as Kaz
- Jake Short as Oliver
- Paris Berelc as Skylar Storm
- Devan Leos as Alan Diaz
- Augie Isaac as Gus
- Carlos Lacamara as Horace Diaz
- After the title Lab Rats: Bionic Island in the episode "Bionic Action Heroes" it will renamed to Lab Rats: Bionic Lair.
- Hal Sparks is absent for two episodes. (Spike vs. Spikette and Chase: The Dream).
- Krane and S-1 are alive.
- Leo and Spin are mentors.
- S-1's name is now Sarah.
- Perry is revealed to be bionic.
- Spike returns in the episodes "Spike vs. Spikette" and "Bionic Action Heroes".
- It is also revealed that Sarah has a commando app called Spikette.
- Marcus returns in Forbidden Hero as a good guy.
- This season includes a crossover with Mighty Med, Mighty Rats.
- Agent Reed, who appeared in the Season 3 episode Bionic House Party, is the season antagonist.
- The academy is destroyed in Bionic Action Heroes.
- Chase and Bree make the plans for a bionic lair in Bionic Dog. Then, it's built in Ultimate Tailgate Challenge by Donald and Tasha.
- Donald gets powers in the crossover.
- Leo now has a bionic chip.
- New Soldiers, Old Faces is a special episode focusing on recurring cast.
- A new language called bionish is revealed.
- Leo, Chase and Bree's dreams are shown.
- Bree and Sebastian start dating.
- Chase gets water generation, Adam gets pyrokinesis and Leo gets molecularkinesis in An Unusual Amount of Missions.
- Caitlin and her mum (and possibly Troy) leave for Canada. However, in Leo Leaves the Lair, Caitlin and Troy move to the bionic lair, Caitlin becomes staff and Troy gets bionics and becomes a student.
- Chase gets laser spheres and Bree gets energy transference.
- At the end of the season, the lair gets destroyed, so they move to Mission Creek High School and rename it to Mission Creek Bionic School (even though Donald wanted it to be Davenport Bionic School).
- Agent Reed turns good at the end of the season.
- There were three one-hour episodes (not including the crossover): Bionic Rebellion, Bionic Action Heroes, and Soldiers, Attack.