The Expanse was on air for six seasons from 2015 to 2022, first on SYFY and later on Prime Video. Based on the sci-fi book series by James S.A. Corey, the show depicts the future consequences of humanity in our Solar System.
Earth deals with the problems of climate change and overpopulation. Mars operates like a military state, and working people from the Asteroid Belt are exploited for labor and seen as expendable and weak by the two major powers.
As tensions rise between the factions, there is another mysterious and alien threat that makes things even more complicated. Known for its detailed world-building and politically complex setting, The Expanse allows time for character development, thus anchoring such a grandiose space opera in small-scale stories of individual lives and stakes.
While the ensemble cast is made up of characters from every planet, station, and belt in the system, there are seven that have their individual storylines. These seven characters have also been explored much deeper to not only be developed fully but represent the more complex and larger themes that are part of the show.
Disclaimer: The article contains the author's opinions. Reader's discretion is advised.
Clarissa Mao, Bobbie Draper, and 5 other iconic characters from The Expanse
7) James Holden

The protagonist of The Expanse, James Holden (Steven Strait), finds himself embroiled in the tense relationship between Earth, Mars, and the Belt.
A former United Nations Navy member, Holden captains the Rocinante amid all kinds of treachery, from a mysteriously ravaged asteroid to an uninhabited foreign planet. Intelligent, compassionate, and firm in his beliefs, Holden strives to make the Solar System a better place in any way he can.
It is a shame that The Expanse TV show did not get to finish Holden’s story from the books, as his importance becomes even greater down the road. He is a worthy lead whose captivating journey sees him discover his place in the universe.
6) Clarissa Mao

Clarissa Mao (Nadine Nicole) undergoes one of the most immense changes throughout the series of The Expanse—from an attempted assassin to a trusted member of the crew on the Rocinante. She is motivated by her father Jules-Pierre Mao's crimes, and starts with almost a singular focus: to destroy James Holden.
With military-grade implants giving her bursts of great strength, she gets close, but after her plan fails, comes a slow, tense evolution of identity. Through her tentative alliance with Amos Burton (Wes Chatham), Clarissa begins to confront the ramifications of her choices. Their relationships evolve based on the combination of trauma and second chances and become the path toward a new way of living.
She does not erase the past, as one of the strengths of The Expanse is not allowing characters to escape the consequences of their past too easily, but she makes a way to live with it.
Clarissa's evolution also demonstrates the series's value of character growth - even for people who have started down the darkest paths.
5) Amos Burton

Amos Burton is the Rocinante’s muscle, but there is more behind the brawler. With a past rooted in violence and exploitation back on Earth, Amos carries trauma that shapes how he moves through the world. He does not pretend to be a good person. He just tries to follow the lead of those he trusts to make the right calls.
What makes Amos compelling is not just his strength in a fight—it is the contrast. Brutal is quietly loyal to his crew, especially protective of those who cannot protect themselves. He forms deep bonds, particularly with Naomi and Clarissa, showing a level of care that cuts through his detached exterior.
The Expanse never paints Amos as redeemed or healed. But it does show him evolving. In space, far from the systems that broke him, he starts to find a kind of structure—purpose through loyalty, trust through action. And while he never stops being dangerous, he becomes someone his crew can rely on without question.
4) Bobbie Draper

Bobbie Draper begins The Expanse as a soldier, built for war. She is headstrong, highly trained, and loyal to Mars above all else. As a Gunnery Sergeant in the Martian Congressional Republic Navy, she is introduced as a force to be reckoned with, both in combat and when she is not in her signature power armor.
What starts off as the blunt presence of a soldier in a military setting develops into one of the more dynamic arcs in the show.
Her arc takes her far afield from a regimented military position. She suffers a traumatic experience while on a battlefield. Later, as she watches her Martian loyalty turned into a carnival of political betrayals, Bobbie begins to think about loyalty differently than she did when she first was shown in the show.
Over time, her sense of loyalty began to shift—not from one flag or uniform to another but to something broader and more human.
Viewers can see this occur as she starts to disengage from the notion of fighting for Mars, and in turn, starts to fight for people, independent of where they come from.
By the time the later seasons unfold, Bobbie becomes more than a weapon. She becomes a protector. Although she keeps her edge, sense of strength, and practical daylight on nonsense, in certain senses she has become a fully actualized individual who has made a cause her own.
3) Chrisjen Avasarala

She is sharp tongued, strategic minded, and hardly ever outmaneuvered by the opposition. As the UN Secretary-General, Chrisjen Avasarala tests the limits of high-stakes negotiation, always appearing several moves ahead of everyone in the room. However, The Expanse does not only present Avasarala as a political juggernaut, it shows her change.
What begins as a militant Earth-first perspective matures into something more human and broader as the stakes rise above territory and borders. Avasarala remains one of the most commanding presence throughout, despite every insult hurled, or political ally lost, because of Shohreh Aghdashloo's unmistakable delivery and vibrancy. A character as formidable as the crises she wrestles with.
2) Naomi Nagata

Naomi Nagata is instrumental in keeping the Rocinante operational and grounded, as well. Born in the Belt, she is shaped by the relentless hard choices to survive, and she chooses to bring both technical expertise and emotional insight to the group.
Many of her decisions reflect her relationship with Marco, her relationship with Amos, and her loyalty to Holden, all related to the struggle over survival versus belonging.
One of the most memorable scenes from the show features Naomi laser the Rocinante into space, without a space suit. This scene alone represents Naomi: clever, brave, and always striving for something better when she could easily retreat into her survival instincts.
1) Camina Drummer

Camina Drummer is not just a Belter; she is the personification of what it means to fight for the Belt with honor. Although she started off as a supporting character in the show, she developed into one of the show's most authoritative voices. She went from Tycho Station to leading her own fleet, because of her loyalty, sacrifice, and an unshakeable belief in her people.
Each of her choices felt earned and every moment on screen was weighty. By the end, her rise to lead the Transport Union felt like the logical endpoint to a story of power, principle, and leadership without sacrificing yourself.
All seasons of The Expanse are available to stream on Prime Video.