Gabriel Lorca

'' Star Trek: Discovery'' is an American television series created for Paramount+ (originally known as CBS All Access) by Bryan Fuller and Alex Kurtzman. Set roughly a decade before the events of the original ''Star Trek'' series and separate from the timeline of the concurrent feature films, ''Discovery'' explores the Federation–Klingon war while following the crew of the USS ''Discovery''. It premiered on September 24, 2017.

The series stars Sonequa Martin-Green as Michael Burnham, a Starfleet mutineer who is given a war-time field assignment as a science specialist on the USS ''Discovery'' and the adopted sister of original series character Spock. Doug Jones, Shazad Latif, Anthony Rapp, and Mary Wiseman round out the main cast. They were joined by Jason Isaacs for the first season and Anson Mount for the second. Characters seen previously in ''Star Trek'' also appear in recurring roles, including Spock's father Sarek, portrayed by James Frain, and Harry Mudd, portrayed by Rainn Wilson.

The following list includes ''Star Trek: Discovery''s main cast, as well as all guest stars deemed to have had recurring roles throughout the series, and a supplementary list of other noteworthy guests.

Overview

: = Main cast (credited)
: = Recurring cast (3+)
: = Guest cast (1-2)

Main characters

Michael Burnham

Michael Burnham (portrayed by Sonequa Martin-Green) is a science specialist aboard the USS ''Discovery''. Burnham was first officer of the USS ''Shenzhou'', where she was referred to as "number one", until she was convicted of mutiny and sentenced to life in prison. ''Discovery'' captain Gabriel Lorca, brings Burnham back to duty with a temporary wartime assignment as a scientist on his ship. Burnham was raised following Vulcan culture and traditions by Sarek, and is the first human to attend the Vulcan Learning Center and Vulcan Science Academy.

Series co-creator Bryan Fuller had anticipated casting announcements for the show in October 2016, but no announcements had been made by the end of that month. The majority of the series main characters were believed to have been cast by then, but no actress had been cast for the series' lead role. This was a source of "some internal stress" at CBS, with the casting of the character deemed "a far tougher assignment" than expected. Several African American and Latina actresses were being looked at for the role, with CBS "not seeking a huge star and referringa fresh face for the part." Martin-Green was cast in the role in December, which was revealed with the character's production codename "lieutenant commander Rainsford". Her casting was officially confirmed in April 2017, following the end of her run on '' The Walking Dead'', with the character's actual name also revealed. The character has an inner conflict due to being raised by Sarek, with showrunner Aaron Harberts explaining that many of the actresses tested for the role "either went way too robotic and chilly or way too emotional", but Martin-Green was "able to be aloof but warm; logical but able to surrender her emotional side to the audience."

Since Sarek's son Spock never mentioned a sister in the original series, executive producer Alex Kurtzman said that the specifics of Burnham's backstory would be revealed in a way that would not break the existing canon continuity. As the show's protagonist, Burnham was not made a starship captain, like those of previous ''Star Trek'' series, "to see a character from a different perspective on the starship—one who has different dynamic relationships with a captain, with subordinates; it gave us richer context", though she does become captain of ''Discovery'' at the end of the last episode of season three. In the first two episodes of the series (stripped of rank by the end of episode two), she is referred to as Number One to honor the character of the same name portrayed by Majel Barrett