Here are some of the series within the Star Trek universe and some things to be aware of when considering watching them. For each, I'll provide a brief overview, some of the characters and cast, and a link to the IMDb page.
1966–1969
This is what started it all, establishing the first concepts of the franchise: the U.S.S. Enterprise, Captain Kirk, Spock, Scotty, "Beam me up," Vulcans, Klingons, Tribbles, and so many classic elements. To many, this classic series holds a dear place in their hearts. To some others, it feels too dated to really connect with. While certainly progressive in its time, some aspects of this show have aged much worse than in others. Keep in mind that it was filmed in the 1960s, allow yourself to laugh a little at some of the low-budget sets, props, and effects, and some corny acting at times, and you should be able to still find some great moments in this series.
This series is directly followed by Star Trek: The Animated Series and the first 6 Star Trek films that feature many of the same cast members.
Captain James T. Kirk (William Shatner)
Spock (Leonard Nimoy)
Dr. Leonard "Bones" McCoy (DeForest Kelley)
Montgomery "Scotty" Scott (James Doohan)
Nyota Uhura (Nichelle Nichols)
Hikaru Sulu (George Takei)
Pavel Chekov (Walter Koenig)
Christine Chapel (Majel Barrett)
1973–1975
This animated series is meant to continue the adventures from The Original Series and features the voices of nearly all the original cast. The quality of the animation isn't very good, however, and I feel like it suffers a lot from that. Overall, it feels a lot like The Original Series—rather campy while still offering some decent stories, but weaker than its predecessor.
Captain James T. Kirk (William Shatner)
Spock (Leonard Nimoy)
Dr. Leonard "Bones" McCoy (DeForest Kelley)
Montgomery "Scotty" Scott / Arex (James Doohan)
Nyota Uhura (Nichelle Nichols)
Hikaru Sulu (George Takei)
Christine Chapel / M'Ress (Majel Barrett)
1987–1994
This series came out nearly 2 decades after The Original Series was canceled and a few decades after the events of that series in-universe. It features a new crew, captained by Jean Luc Picard, aboard a new Enterprise. Very iconic in its own right and, in many ways, vastly improves on the franchise and establishes many themes, characters, races, and lore that will continue throughout the rest of the franchise. For these and many other reasons, I think that this series might be the best place to start for many new viewers.
While it is certainly more contemporary than The Original Series, it is also not without some episodes or moments that did not age well (or that were outright not great at the time, either). I recommend skipping the first 2 seasons for a first viewing and maybe coming back to those later. There was actually a documentary that was made specifically about how chaotic the production of the first two seasons was, called Chaos on the Bridge, which you can watch on YouTube.
This series spun off two other series (Deep Space Nine and Voyager) and was followed by the next 4 Star Trek films that feature many of the same cast members (Generations, First Contact, Insurrection, and Nemesis). Much later, many of these same characters return in the series Star Trek: Picard.
Captain Jean Luc Picard (Patrick Stewart)
William Riker (Jonathan Frakes)
Data (Brent Spiner)
Deanna Troi (Marina Sirtis)
Worf (Michael Dorn)
Geordi La Forge (LeVar Burton)
Beverly Crusher (Gates McFadden)
Wesley Crusher (Wil Wheaton)
Guinan (Whoopi Goldberg)
Tasha Yar (Denise Crosby)
Katherine Pulaski (Diana Muldaur)
Miles O'Brien (Colm Meaney)
1993–1999
A spin-off of Star Trek: The Next Generation, this series takes on a rather different take on the franchise by focusing on characters living and operating aboard a Cardassian space station that has been reclaimed by the Bajoran people and Starfleet. It is a bit darker than the previous series and focuses more on topics like religion, war, family, alliances, political intrigue, espionage, and Ferengi shenanigans. It also (at least initially) did not feature a mobile starship that had been a staple in the franchise for every series before it. While this change didn't particularly sit well with some long-time fans, the fact that the station is sitting right next to a stable wormhole to the yet unknown Gamma Quadrant and the focus on things like the Bajoran/Cardassian conflict, local politics, and family allowed more opportunities to have longer, multi-part stories that make Deep Space Nine a more well-integrated overall series-long story.
It also takes some progressive strides in ways like...
Having a black captain character, who is also a single father and has a healthy relationship with his son (which was not commonly displayed in media at that time)
Taking a very respectful yet also critical position concerning religion and politics
Creating a character who at least partially represents transgender people
Creating a character who at least partially represents homosexual people
Critiquing capitalist culture and male patriarchy
As with The Next Generation, the first couple of seasons are a little more rough than later ones. For this reason, I might suggest mostly taking a dive into the series a little bit later, at least to start out and get a better taste for the series as a whole. That being said, with how many storylines build on each other throughout the series, it is more difficult to jump around or only watch select episodes without it lessening the overall impact of those stories.
Commander/Captain Benjamin Sisko (Avery Brooks)
Cirroc Lofton (Jake Sisko)
Kira Nerys (Nana Visitor)
Odo (René Auberjonois)
Quark (Armin Shimerman)
Miles O'Brien (Colm Meaney)
Jadzia Dax (Terry Farrell)
Julian Bashir (Alexander Siddig)
Worf (Michael Dorn)
Ezri Dax (Nicole de Boer)
Elim Garak (Andrew Robinson)
Nog (Aron Eisenberg)
Rom (Max Grodénchik)
Gul Dukat (Marc Alaimo)
Winn Adami (Louise Fletcher)
Weyoun (Jeffrey Combs)
1995–2001
This series takes place about the same time as Deep Space Nine, but is focused on the crew of the U.S.S. Voyager and their adventures as they do whatever it takes to return home from being flung into the farthest side of the galaxy in the Delta Quadrant.
Some of these characters went on to become featured in Star Trek: Picard and Star Trek: Prodigy.
Not everyone appreciated the twist on the franchise taken by Deep Space Nine, but Voyager offered a bit more of a familiar episodic, exploratory-focused adventure. Voyager took some slightly different risks with changing up the series by removing any chance for Starfleet or Federation back-up, having mostly unknown alien species, and having two separate crews initially at each other's throats a bit. At the same time, they also switched things up midway through the show and started adding more things that they believed their audience wanted, including more exploration of the Borg and introducing a new Borg character to the main cast (as well as, admittedly, a bit of eye-candy).
Overall, Voyager is still more progressive than The Next Generation and added concepts like having the first female captain lead character.
Captain Kathryn Janeway (Kate Mulgrew)
Chakotay (Robert Beltran)
Seven of Nine (Jeri Ryan)
The Doctor (Robert Picardo)
Tom Paris (Robert Duncan McNeill)
Tuvok (Tim Russ)
B'Elanna Torres (Roxann Dawson)
Harry Kim (Garrett Wang)
Neelix (Ethan Phillips)
Kes (Jennifer Lien)
Seska (Martha Hackett)
Naomi Wildman (Scarlett Pomers)
Icheb (Manu Intiraymi)
2001–2005
This series takes place a few decades before The Original Series and provides the earliest glimpses of how humanity went from having barely left our solar system to taking its first plunge into the rest of the galaxy, much to the dismay of the Vulcans. The United Federation of Planets doesn't even exist yet, so humanity and the Vulcans have a tenuous alliance during these very early years of Starfleet.
Again, the running trend with most of these shows is that the first couple of seasons do not demonstrate the show at its best. Enterprise had a relatively short run of only 4 seasons, so it's more difficult to suggest that someone start more than halfway through the show to get to the better stuff. That being said, season 3 is probably the show at its best.
Captain Jonathan Archer (Scott Bakula)
T'Pol (Jolene Blalock)
Charles "Trip" Tucker III (Connor Trinneer)
Phlox (John Billingsley)
Malcolm Reed (Dominic Keating)
Hoshi Sato (Linda Park)
Travis Mayweather (Anthony Montgomery)
Shran (Jeffrey Combs)
Silik (John Fleck)
2017–2024
To be completely honest, I might never actually recommend this show, but if you feel up for it, I think it's best to watch in a completely linear fashion from start to finish since the episodes are much more connected with season- and series-long story arcs.
This series takes place not too long after the events of Star Trek: Enterprise and focuses on the crew of the U.S.S. Discovery and our main lead, Michael Burnam. The level of progressive normality in this show is well above any series that preceded it, with many more opportunities for a diverse audience to experience inclusion and be seen in characters who are openly homosexual, transexual, or non-binary and a young black female lead (yes, Michael is a woman). The show also features a more modern and polished visual appearance than older series, but only has a fraction of the episodes per season. Also, each season is a primary story arch, so they are meant to be watched sequentially, which differs from the previously more episodic approach. Discovery also is much darker and grittier than Star Trek has ever been before, and that, combined with some questionable writing, uneven direction, "save the world again" season-long plots, attempted re-envisioned Klingons, and retroactive changes to the franchise (like with Michael's relationship to Spock) have caused some long-time fans to have a hard time feeling like they can relate or feeling like the franchise isn't forever going in a new, unfamiliar direction. Still, many new and younger fans may be able to get into the franchise more easily since the show more closely emulates other dark and dramatic shows that they have been accustomed to more recently, like Game of Thrones.
Michael Burnam (Sonequa Martin-Green)
Saru (Doug Jones)
Georgiou (Michelle Yeoh)
Gabriel Lorca (Jason Isaacs)
Sylvia Tilly (Mary Wiseman)
Paul Stamets (Anthony Rapp)
Hugh Culber (Wilson Cruz)
Keyla Detmer (Emily Coutts)
Gen Rhys (Patrick Kwok-Choon)
Joann Owosekun (Oyin Oladejo)
Ash Tyler (Shazad Latif)
Jett Reno (Tig Notaro)
Charles Vance (Oded Fehr)
Adira (Blu del Barrio)
Airiam (Sara Mitich)
Nilsson (Sara Mitich)
R. A. Bryce (Ronnie Rowe)
Cleveland Booker (David Ajala)
J. G. Linus (David Benjamin Tomlinson)
Captain Christopher Pike (Anson Mount)
Spock (Ethan Peck)
2022–Present
This series takes place mostly concurrently with Star Trek: Discovery and just slightly before the events of The Original Series. It features the earlier adventures of the original U.S.S. Enterprise when it was still commanded by Captain Christopher Pike. Other characters from The Original Series include Spock, Uhura, Christine Chapel, and a cameo from James T. Kirk. It also brings back a bit more of a familiar episodic starship adventure like The Original Series and The Next Generation, but with some updated progressive values made more apparent. While the unaired pilot of The Original Series featured Captain Pike saying something rather sexist about how he "can't get used to a woman being on the bridge," Strange New Worlds features a much more open-minded Captain Pike who happens to be on the bridge of the Enterprise with more women than men.
While Strange New Worlds might bring back some familiar formulas to how they tell their stories, they also have brought in some more daring or experimental approaches. This series features the first time that an episode is told through a musical performance approach.
Captain Christopher Pike (Anson Mount)
Spock (Ethan Peck)
Una Chin-Riley (Rebecca Romijn)
Nyota Uhura (Celia Rose Gooding)
Christine Chapel (Jess Bush)
La'an Noonien-Singh (Christina Chong)
Erica Ortegas (Melissa Navia)
M'Benga (Babs Olusanmokun)
George Samual "Sam" Kirk (Dan Jeannotte)
Hemmer (Bruce Horak)
Chief Kyle (André Dae Kim)
Pelia (Carol Kane)
James T. Kirk (Paul Wesley)
2020–2023
To be completely honest, I might never actually recommend this show, but if you feel up for it, I think it's best to just watch season 3 from start to finish, but perhaps only after having watched The Next Generation, Voyager, and Deep Space Nine to get a more full appreciation for what will be presented.
Alternatively, you could watch it in a completely linear fashion from start to finish since the episodes are much more connected with season- and series-long story arcs.
2020–2024
To be completely honest, I might never actually recommend this show, at least not until you've seen a decent amount of other content from the franchise since it heavily references other shows and films.
2021–2024
This show is animated and intended for a younger audience demographic (probably early teens). However, it's remarkably suitable for more adult audiences as well.
The story is centered around a ragtag team of young aliens trying to escape a mining prison and a tyrannical overlord while unraveling complex mysteries surrounding an abandoned Starfleet vessel, a holographic Captain Janeway with missing memory files, the motivations of a being known as The Diviner, and many more. It is engaging, fun, creative, rather well-written, and feels very attuned to the Star Trek franchise.
There are a decent number of references to Star Trek: Voyager, including some of the same characters from that show (and others in the franchise), so it may be helpful to be familiar with that first, though it's not necessary for understanding the plot of Prodigy as a whole.
Dal R'El (Brett Gray)
Gwyndala (Ella Purnell)
Rok-Tahk (Rylee Alazraqui)
Zero (Angus Imrie)
Jankom Pog (Jason Mantzoukas)
Murf (Dee Bradley Baker)
Kathryn Janeway / Hologram Janeway (Kate Mulgrew)
Chakotay (Robert Beltran)
The Doctor (Robert Picardo)
The Diviner (John Noble)
Drednok (Jimmi Simpson)
Ascencia (Jameela Jamil)
Maj'El (Michaela Dietz)