NCIS Season 18 premiered on November 17, 2020. CBS has ordered 16 for this season due to ongoing COVID-19. The season concluded on May 25, 2021.
|Leroy Jethro Gibbs||Mark Harmon||NCIS Special Agent in Charge.||Inactive and suspended indefinitely.|
|Timothy McGee||Sean Murray||NCIS Senior Special Agent.|
|Nicholas Torres||Wilmer Valderrama||NCIS Special Agent.|
|Eleanor Bishop||Emily Wickersham||NCIS Special Agent.|
|Jacqueline Sloane||Maria Bello (episode 1–8 only)||NCIS Forensic Psychologist.|
|James Palmer||Brian Dietzen||Chief Medical Examiner.||Former Medical Assistant.|
|Kasie Hines||Diona Reasonover||NCIS Forensic Specialist|
|Leon Vance||Rocky Carroll||Director of NCIS.|
|Donald Mallard||David McCallum||NCIS Historian and Archivist.||Former Chief Medical Examiner.|
- Maria Bello (Jack Sloane) has depart the series after eight episodes.
- Emily Wickersham (Eleanor Bishop) departed the series after season finale.
- On May 6, 2020, the main series has renewed for 18th season as well as L.A. and New Orleans.
- Filming on this season resumed on Wednesday, September 9, 2020.
- The series premiered on November 17, 2020.
- This season is got only 16 episodes, making this the shortest season in the show's history.
- On May 19, 2021, it was also announced that this will be the final season to have its Tuesday timeslot 
- This is Maria Bello (Jacqueline Sloane) and Emily Wickhersham's (Ellie Bishop) final season, respectively.
- With the departure of Gibbs from the team, there are no original team members left.
- Though McGee is the longest serving member, he was not on the team until season 2 episode 1.
|399||1||1802||Sturgeon Season (episode)||November 17, 2020||Gibbs and Fornell attempt to track down the leader of a drug ring who supplied drugs to Fornell's daughter. Also, the team deals with the case of a missing cadaver from the NCIS autopsy room.|
|400||2||1801||Everything Starts Somewhere (episode)||November 24, 2020||Flashbacks reveal the murder case that first introduced young Gibbs to NCIS and his introduction to young, new-to-America Ducky.|
|401||3||1803||Blood and Treasure (episode)||December 8, 2020||The discovery of two dead bodies in a forest leads the team into the wild world of modern-day treasure hunting, and Gibbs and Fornell get deeper into their search for the opioid kingpin.|
|402||4||1804||Sunburn (episode)||January 19, 2021||McGee and Delilah's Bahamian vacation turns into a high-stakes mission when a case NCIS is tracking of a dead escape room manager has ties to the island. Also, Gibbs fears the worst when his search for Fornell leads to blood.|
|403||5||1805||Head of the Snake (NCIS episode)||January 19, 2021||Gibbs and Fornell's crusade to find the head of the drug ring responsible for Emily's overdose comes to a climax. Also, Gibbs and Vance finally let the team in on a case that has dangerous implications.|
|404||6||1806||1mm (episode)||January 26, 2021||Following a tip about smuggled weapons, Bishop and Torres engage in a shootout in a former sheriff's residence that's now a historical site, only to find themselves locked in abandoned jail cells there.|
|405||7||1807||The First Day (episode)||February 9, 2021||The team investigates the murder of a Navy officer who was killed while driving home a recently released inmate. Also, Gibbs helps Palmer deal with a personal trauma.|
|406||8||1808||True Believer (episode)||March 2, 2021||When Sloane's name is discovered in Afghanistan at the site of an abandoned bus with a dead driver, Gibbs accompanies her on a trip to find a group of girls who were kidnapped from the bus. Also, McGee, Bishop and Torres track down a hacker who emailed compromising information to the Taliban.|
|407||9||1809||Winter Chill (episode)||March 9, 2021||The team dives into the competitive world of food trucks after finding a man frozen to death in the back of one.|
|408||10||1810||Watchdog (episode)||March 16, 2021||The team uncovers a secret dogfighting ring, which leads to an unexpected move by one of the team members.|
|409||11||1811||Gut Punch (episode)||April 6, 2021||Vance assigns McGee, Torres and Bishop to COVID compliance duty at a foreign affairs summit, where they discover a link to another NCIS team's murder case.|
|410||12||1812||Sangre (episode)||April 27, 2021||Evidence from the stabbing of a Marine Sergeant leads Torres to meet his father, who left when he was a child.|
|411||13||1813||Misconduct (episode)||May 4, 2021||While the team investigates a biker killed in a hit and run, Gibbs prepares to testify against a financial advisor who stole millions from his Navy clients.|
|412||14||1814||Unseen Improvements (episode)||May 11, 2021||The team tracks a stolen laptop to the uncle of a young boy who is Gibbs' former neighbor.|
|413||15||1815||Blown Away (episode)||May 18, 2021||When members of an NCIS Regional Enforcement Action Capabilities Training Team (REACT) are killed during an explosion, Special Agent Jessica McKnight, the lone surviving member, helps crack the case using high tech body armor.|
|414||16||1816||Rule 91 (episode)||May 25, 2021||While pursuing a dangerous arms dealer, the team is shocked when Bishop is implicated in an old NSA leak. Also, Gibbs and Marcie realize the killer they've been tracking may be onto them.|
|Seasons of NCIS|
|NCIS Season 1 ♦ NCIS Season 2 ♦ NCIS Season 3 ♦ NCIS Season 4 ♦ NCIS Season 5 ♦ NCIS Season 6 ♦ NCIS Season 7 ♦ NCIS Season 8 ♦ NCIS Season 9 ♦ NCIS Season 10 ♦ NCIS Season 11 ♦ NCIS Season 12 ♦ NCIS Season 13 ♦ NCIS Season 14 ♦ NCIS Season 15 ♦ NCIS Season 16 ♦ NCIS Season 17 ♦ NCIS Season 18 ♦ NCIS Season 19