Much like the sci-fi show's ambitious plot, The Expanse cast grew larger with each succeeding season, and the sixth and last season is no exception. Based on the book series of the same name written by Ty Franck and Daniel Abraham under the pen name James S.A. Corey, The Expanse centers on the vast political conflicts between the powers of Earth, Mars, and the Asteroid Belt 300 years in the future. In The Expanse season 6, these conflicts culminate in a system-wide war waged by Belter terrorist Marco Inaros and the Free Navy, whose asteroid attack on Earth has left the planet in shambles.
Newly reinstated UN Secretary General Chrisjen Avasarala looked to coordinate the joint Earth-Mars fleet with James Holden and the crew of the Rocinante in an effort to defeat the Free Navy. Concurrently, Camina Drummer and what remained of her crew evaded Marco's forces in the Belt after betraying them at the end of season 5. The Expanse season 6 did introduce several new characters by way of its supporting cast, but series mainstays primarily took center stage over the show's 6-episode final run.
Steven Strait As James Holden
Steven Strait returned to The Expanse cast as the series' lead character since season 1. As captain of the Rocinante, James Holden piloted the salvaged Martian warship alongside Naomi Nagata, Amos Burton, Clarissa Mao, and Bobbie Draper in the fight against Marco's fleet, after sticking to the sidelines for much of season 5. The Expanse season 6 saw Holden growing exponentially, and having a much better understanding of the intricacies of intergalactic leadership post-war. This allowed the character to escape space opera conventions and have a more realistic and compelling final arc. Outside of The Expanse, Strait is most widely recognized for his leading roles in The Covenant and 10,000 BC, and he also appeared in Here Awhile and Life Like.
Dominique Tipper As Naomi Nagata
Dominique Tipper's Naomi Nagata went through the wringer in The Expanse season 5, as her ex-lover Marco held her captive aboard his ship when she attempted and failed to rescue their son Filip. After enduring an onslaught of physical and emotional trauma, Naomi's dilemma in The Expanse season 6 revolves around fighting a war against Belters, of whom she is one. In the end, Naomi's cunning and intelligence forces her to have the biggest hand in ending the war. Apart from being an indispensable part of The Expanse cast, Dominique Tipper's other notable appearances include Headhunters, Fantastic Beasts and Where to Find Them, and The Girl With All the Gifts.
Wes Chatham As Amos Burton
After surviving Marco's initial asteroid attack on Earth in The Expanse season 5, Wes Chatham's Amos Burton returned to outer space as the Rocinante's mechanic, bringing Clarissa Mao along with him. The Expanse season 6 saw Amos give Clarissa the same type of guidance and leadership that Amos once needed from his Naomi. Indeed, Amos is inarguably the character who has grown the most throughout The Expanse, especially after the reveal of his traumatic backstory in season 5, and his crucial role in the final events of season 6. One of The Expanse cast's four remaining original members, Chatham also played the role of Castor in The Hunger Games: Mockingjay Part 1 and Mockingjay Part 2.
Frankie Adams As Bobbie Draper
Former MCRN gunnery sergeant Bobbie Draper is played by Frankie Adams in The Expanse season 6. A series regular since season 2, Bobbie is known for her no-nonsense attitude and lethal fighting skills. Her journey in The Expanse season 6 saw her reconvene with Chrisjen Avasarala, and eventually the crew of the Rocinante on a pivotal mission in the war. Frankie Adams held a role in the 2018 film Mortal Engines and will appear in the TV adaptation of The Lost Flowers of Alice Hart starring Sigourney Weaver and Alycia Debnam-Carey. Adams also appeared in the TV mini-series Teine Sa and The Panthers.
Shohreh Aghdashloo As Chrisjen Avasarala
Another series mainstay since The Expanse's premiere in 2015, Chrisjen Avasarala returned in The Expanse season 6 as UN Secretary General. One of the most complex characters in The Expanse cast, Avasarala transforms from a politician willing to torture Belters for information into one of the last hopes for humanity's reunification. All of Avasarala's cunning is put to great use in The Expanse season 6. An Emmy-Award-winner and Oscar nominee, Aghdashloo counts roles in the 2003 film House of Sand and Fog and the 2008 miniseries House of Saddam among her most memorable appearances. She has also voiced characters in the Mass Effect and Destiny video game series.
Cara Gee As Camina Drummer
Cara Gee's Camina Drummer first appeared in The Expanse season 2 as then-OPA leader Fred Johnson's second-in-command, and has since developed into a complex main character with her own central arc. Drummer eventually becomes crucial in the fight against Marco's forces. In fact, The Expanse season 6 ends with the beginning of the biggest chapter yet for Drummer, whom some audiences argue is the true protagonist of The Expanse. A member of The Expanse cast since season 4, Cara Gee's other notable appearances include a lead role in 2020's The Call of the Wild alongside Harrison Ford and Omar Sy. Gee also appeared in Strange Empire and Red Rover.
Keon Alexander As Marco Inaros
Since The Expanse season 4, Keon Alexander has portrayed the Belter extremist Marco Inaros, who became notorious after orchestrating the devastating asteroid attack on Earth and killing billions. Whether aboard his warship the Pella or on the Belt's new capital, Ceres station, Marco's season 6 endeavors included rallying Free Navy support against the forces of Earth and Mars. Although Marco is a simple, straightforward, and selfish character, what he represents is complex, as his form of extremism is the fruit of the inner planets' centuries-long oppression of Belters. Apart from his pivotal role in The Expanse cast, Keon Alexander notably appeared in The Tyrant, Impulse, and The Artist's Way Out.
Nadine Nicole As Clarissa Mao
Locked behind bars on Earth in The Expanse season 5 before escaping with Amos when the asteroids hit, Nadine Nicole's Clarissa Mao joined the Rocinante crew under tense circumstances after her violent pursuit of Holden in season 3. Clarissa's revenge arc reached its peak in The Expanse season 6 as she aimed to prove her worth to the people she once sought to destroy. Clarissa also became crucial to Amos' journey of self-acceptance. Nadine Nicole's resume also includes appearances in Hulu's Casual, NBC's The Village, and The Young and the Restless.
Jasai Chase-Owens As Filip Inaros
Jasai Chase-Owens returned in The Expanse season 6 as Filip Inaros, the teenage son of Marco and Naomi. Filip is the wild card in The Expanse cast during the last season. Torn between his loyalty to Marco and the guilt of having been part of an atrocity that killed countless Earthers, Filip's perspective becomes essential in terms of fully understanding the Free Navy rise, growth, and eventual collapse. Jasai Chase-Owens appeared in the 2016 film Loserville and the television series Uncoupled and The Deuce.
Anna Hopkins As Monica Stuart
The Expanse season 6 is the show's third season featuring Anna Hopkins' Earth-born journalist Monica Stuart. After what started as a documentary gig aboard the Roci in season 3, Monica accompanied Holden on the ship in season 5. In The Expanse season 6, Chrisjen Avasarala enlists Monica's help to build understanding between Belters and Earthers amid all-out war. Anna Hopkins previously held roles in Shadowhunters and Arrow. After her stint in The Expanse cast, Hopkins appeared in the shows Ride, Children Ruin Everything, and Pretty Hard Cases.
Vanessa Smythe As Michio
First appearing in The Expanse season 5 as a member of Drummer's polyamorous crew, Vanessa Smythe's Michio gets her name from the book character Michio Pa—whose arc has been devoted to Drummer in the TV series. Michio came to Drummer's aid in the season 5 finale, killing Karal with a fire extinguisher. The Expanse season 6 saw Michio and Drummer growing closer as the war came to a head. Vanessa Smythe appeared in 2020's Pieces of a Woman and held a minor role in seasons 2 and 3 of Designated Survivor.
Samer Salem As Josep
Known for brief appearances in The Boys season 2 and The Handmaid's Tale season 4, Samer Salem reprises the role of Josep in The Expanse season 6. Josep, along with Michio, opted to stay with Drummer in the fallout of their faction's betrayal of Marco. The last season saw Josep becoming a pivotal player in a decisive battle against the Free Navy.
The Expanse Season 6 New Cast & Characters
Kathleen Robertson as Rosenfeld Guoliang - We're All In This Together, Northern Rescue, and Beverly Hills 90210 actor Kathleen Robertson makes her debut on The Expanse as Rosenfeld Guoliang, Marco's new second-in-command aboard the Pella. Rosenfeld somewhat serves as the voice of reason in Marco's unpredictable crew. She may have a minor role in The Expanse cast, but it was essential in painting a complete picture of the series' big bad, Marco Inaros.
Joanne Vannicola as Nico Sanjrani - Played by Joanne Vannicola, Nico Sanjrani was the acting head of Ceres Station in The Expanse season 6. Joanne Vannicola, a Daytime Emmy winner, is known for Being Erica, Slasher, and the 2015 movie Stonewall. In a show renowned for its diverse array of characters, Sanjrani serves as The Expanse's first non-binary figure, also portrayed by a non-binary actor.
Emma Ho as Cara - Emma Ho's Cara lies at the center of The Expanse season 6's Laconia storyline as a child born on the planet to Earther parents. At Laconia, Cara and her family bore witness to alien creatures and technologies as the war raged on back in Earth's solar system. Cara, Laconia, and Duarte's storylines would've been further expanded and explored had the series continued after The Expanse season 6. Emma Ho also appeared in Star Trek: Strange New Worlds and voiced characters in Rosie's Rules and PJ Masks.