Working in security on a Federation starship or space station is not an easy task, and different Star Trek Security Chiefs handle the job with varying levels of success. The galaxy is full of dangerous aliens and mysterious anomalies, and Starfleet security officers must do their best to be prepared for any threat. While the Chief of Security is often skilled in hand-to-hand fighting, they must also be able to sniff out potential threats and have a mind for combat tactics. Though not every security chief mans the ship's weapons stations, some do serve as the chief tactical officer as well.

Starfleet Officers must be prepared to encounter all manner of dangers in their mission to explore strange new worlds, and the security team usually serves as the first line of defense. Star Trek: The Original Series' USS Enterprise did not have a prominent Chief of Security, which might explain why so many red shirt-wearing officers lost their lives on TOS. By the time of Star Trek: The Next Generation, the Security Chief became one of the most important positions on the ship and the character who fills the position is usually a member of the main cast. Here are 11 of the best (and not so great) Chiefs of Security in Star Trek.

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11 Commander Ellen Landry - Star Trek: Discovery

Commander Ellen Landry (Rekha Sharma) was Chief of Security of the USS Discovery in early in Star Trek: Discovery season 1, and she didn't exactly distinguish herself in the role. Cold and rude to Michael Burnham (Sonequa Martin-Green) when Starfleet's first mutineer was transferred to Discovery, Landry's arrogance quickly got her killed by a giant tardigrade named Ripper. Landry lasted just two episodes of Star Trek: Discovery, and she ended up being the show's version of a red shirt despite her blue Starfleet uniform.

10 Rok-Tahk - Star Trek: Prodigy

The youngest Security Chief in Star Trek history, Rok-Tahk (Rylee Alazraqui) took on the assigment when she and her young friends commandeered the USS Protostar. As Brikar, Rok-Tahk's intimidating size and great strength make her an ideal Chief of Security on the surface. However, Rok-Tahk's true talents lie in the sciences, and it soon became apparent that playing the role of Security Chief was a waste of Rok-Tahk's abilities in Star Trek: Prodigy. Rok-Tahk's budding genius saved the ragtag teenage crew of the Protostar on more than one occasion, and she transitioned into the more suitable roles of Science Officer and xenobiologist before the end of Star Trek: Prodigy season 1.

9 Commander D. Nhan - Star Trek: Discovery

Commander Nhan (Rachael Ancheril) replaced Ellen Landry as Chief of Security of the USS Discovery. A Barzan, Nhan was serving as an engineer on the USS Enterprise when she joined Captain Christopher Pike (Anson Mount) and transferred to the Discovery during the Red Angel mission. Nhan traveled with the Discovery to the 32nd century, where she then left the ship and became a replacement Barzan on the USS Tikhov. In Star Trek: Discovery season 4, Nhan briefly returned to the Discovery during the Dark Matter Anomaly crisis, but she felt her place was elsewhere besides Captain Burnham's ship.

8 Pavel Chekov - Star Trek: The Original Series

Although Pavel Chekov (Walter Koenig) mostly serves as the navigator on Star Trek: The Original Series, he takes on many different roles during the TOS films. Chekov briefly serves as Security Chief and Tactical Officer on the USS Enterprise sometime before the events of Star Trek: The Motion Picture. Chekov also studies the sciences and serves as the acting Science Officer on the Enterprise after Spock's death in Star Trek II: The Wrath of Khan. After the events of Star Trek IV: The Voyage Home, Chekov resumes his post as a navigator on the USS Enterprise-A. While Chekov is undoubtedly an accomplished and likable Starfleet officer, his skills seem better suited to a position other than security.

7 Lt. Tasha Yar - Star Trek: The Next Generation

In Star Trek: The Next Generation season 1, Lt. Tasha Yar (Denise Crosby) served as Chief of Security on the USS Enterprise-D under the command of Captain Jean-Luc Picard (Patrick Stewart). Yar was a skilled martial artist and an excellent hand-to-hand fighter, and she was never afraid to face threats to the Enterprise head-on. However, Tasha often reacted emotionally to threatening situations without fully thinking through her actions. On several occasions, Captain Picard had to tell Lt. Yar to stand down when she wished to fight a dangerously powerful opponent. Tasha would likely have grown into a legendary Security Chief but Yar was tragically killed near the end of TNG season 1.

6 Lt. Shaxs - Star Trek: Lower Decks

Lt. Shaxs (Fred Tatasciore) fought in the Bajoran resistance during the Cardassian Occupation of Bajor, before eventually becoming the Security Chief on the USS Cerritos. Shaxs often suggests the most violent solution to problems that arise, and his go-to recommendation is usually ejecting the warp core, but the burly Barjoran cares deeply about the Cerritos and her crew, especially his main squeeze, Dr. T'Ana (Gillian Vigman). Shax has taken Lieutenants Sam Rutherford (Eugene Cordero) and Brad Boimler (Jack Quaid) under his wing as part of his "bear pack." Shaxs makes sure that his security team members have time to unwind, but they always react quickly and methodically when a threat arises.

5 Lt. Malcolm Reed - Star Trek: Enterprise

As the senior Armory Officer aboard the Enterprise NX-01, Lt. Malcolm Reed (Dominic Keating) was the forerunner of the Starfleet Security Chief. Reed's innovations include the "Reed Alert," which became the standard starship Red Alert. On Star Trek: Enterprise, Malcolm often has to improvise and come up with tactical solutions on the fly. In the years before the founding of the United Federation of Planets, and Captain Jonathan Archer (Scott Bakula) and his crew encounter a lot of firsts. Reed sometimes adopts a shoot-first attitude, but his history with the Starfleet Intelligence organization Section 31 gives him a tactical edge.

4 Lt. La'an Noonien-Singh - Star Trek: Strange New Worlds

In the first two seasons of Star Trek: Strange New Worlds, Lt. La'an Noonien-Singh (Christina Chong) has proven herself to be a smart and capable Security Chief who can hold her own in a fight. As a child, La'an was the only survivor of a brutal Gorn attack and has since become an expert in fighting the Gorn. La'an has twice served as Acting First Officer of the USS Enterprise to substitute for Number One (Rebecca Romijn), but she takes her job as Security Chief on the Enterprise very seriously. La'an vigilantly keeps a sharp eye out for any threats to the ship. Although she struggles to let people in, La'an cares deeply about her crew and would do almost anything to protect them.

3 Lt. Worf - Star Trek: The Next Generation

As a character, Worf (Michael Dorn) did not truly come into his own until he transferred from the Enterprise to space station Deep Space 9. While it makes sense for the Klingon warrior to be in charge of security, his skills could be put to better use elsewhere. Despite his strength, Worf gets taken down by many villainous aliens over the years, and his Klingon sense of honor sometimes conflicts with his Starfleet duties. After Worf switches to the command track and becomes a regular on Star Trek: Deep Space Nine, he develops into a more successful Starfleet Officer. When Worf returns in Star Trek: Picard season 3, he has joined Starfleet Intelligence, and his job managing field assets, like Commander Raffi Musiker (Michelle Hurd), seems to suit him well.

2 Lt. Commander Tuvok - Star Trek: Voyager

Lt. Commander Tuvok (Tim Russ) serves as Chief of Security and Chief Tactical Officer on the USS Voyager under the command of Captain Kathryn Janeway (Kate Mulgrew). As a Vulcan, Tuvok not only has an extremely logical and analytical mind, but also possesses enhanced strength and stamina. Tuvok was undercover on the Maquis ship Val Jean when it was thrown into the Delta Quadrant. After the USS Voyager follows the Val Jean, Tuvok rejoins Captain Janeway as her second officer. Despite his Vulcan stoicism, Tuvok sometimes grows annoyed with Voyager's chef Neelix (Ethan Phillips) and often delivers clever sarcastic remarks. Throughout Voyager's seven-year journey through the Delta Quadrant, Tuvok maintains security on the ship, even when facing dangerous unknown threats.

1 Constable Odo - Star Trek: Deep Space Nine

Not only does Constable Odo (René Auberjonois) have excellent observation skills and attention to detail, but his Changeling abilities also give him an edge over other security officers. As the Chief of Security on space station Deep Space 9, Odo strives to maintain order and values justice above all else. As an impartial third party, he is not beholden to the laws of Starfleet, and he makes his own rules when it comes to the space station. Odo almost never carries a weapon but is still tough on those who break the rules, and he has a stellar reputation for always getting his man. Despite this, Odo has a big heart and a reserved, almost shy personality. Throughout seven seasons of DS9, Odo always maintains strict security on the station, and he remains one of the best detectives and the best Security Chief in all of Star Trek.