Cast and characters
Seth MacFarlane as Captain Edward "Ed" Mercer:The commander of the Orville. Mercer was an up-and-coming officer, on the fast track to commanding his own heavy cruiser by age 40. Following the end of his marriage due to his wife Kelly's relationship with an alien, he is cited for being lax in performance of his duties and for being hung over while on duty. Despite this, he is informed that the Orville, a mid-level exploratory ship, needs a new commanding officer, and that he is the man for the job.
Adrianne Palicki as Commander Kelly Grayson:The first officer of the Orville and Ed Mercer's ex-wife. The two divorced after Mercer caught Grayson in bed with a Retepsian named Darulio, triggering Mercer's year-long emotional crisis. Unbeknownst to Mercer, Grayson personally appealed to Admiral Halsey, asking him to give her ex-husband a command, insisting that, despite personal setbacks, he deserved it. Grayson asked that her involvement remain confidential. When Grayson is assigned as the Orville's first officer, she and Mercer agree to set aside their differences, to work as a team, and stay friends.
Penny Johnson Jerald as Doctor Claire Finn:The chief medical officer on the Orville, holding the rank of lieutenant commander. She has expertise in molecular surgery, DNA engineering and psychiatry. These exceptional credentials gave her her choice of assignments on heavy cruisers. Instead, she chose a mid-level exploratory vessel. As she explains to Mercer in the pilot episode, she prefers to serve where she feels she is needed, finding such assignments more stimulating. When she tells Mercer that she felt that he could use her assistance on his first command, he misinterprets this as indicating her lack of confidence in him, although she denies this. She never found the ideal person to marry, and she chose to become a single mother, but she later starts dating Isaac in season 2, and marries him in season 3. Her two sons Marcus and Ty travel aboard the Orville with her. Although she repeatedly rebuffs Lt. Yaphit's advances, they become physically intimate in "Cupid's Dagger", after falling victim to a Retepsian sex pheromone.
Scott Grimes as Lieutenant Gordon Malloy:The helmsman of the Orville and Mercer's best friend. Considered the best helmsman in the fleet, he was relegated to desk duty after he attempted to impress a girl with a precarious shuttle docking maneuver, damaging the vessel and losing cargo in the process. Mercer specifically requested Malloy's assignment to the Orville, despite Admiral Halsey's lingering concern over Malloy's history of sophomoric pranks. He is generally comfortable with his reputation for limited intelligence, to the point where he willingly answers a series of questions from Grayson, with the expectation that his answers will demonstrate in a Moclan court that males are not always intellectually superior to females.
Peter Macon as Lieutenant Commander Bortus:The second officer aboard the USS Orville. Bortus is from Moclus, a planet where the primary industry is weapons manufacturing, and whose society is dominated by males. This is explained in the first season as the result of the rarity of female births, one of which occurs when Bortus and his Moclan spouse, Klyden, bear a female at the end of the series' second episode. Per Klyden's wishes, but against Bortus's, the infant undergoes a procedure to transform it into a male following a controversial legal ruling on their home planet. This development, and the attitudes prevalent among Moclans toward females that Klyden himself harbors, subsequently persist as a source of tension for the couple, and is a sensitive matter for Bortus in particular, who harbors resentment over it. It is later revealed in the second-season episode "Sanctuary" that female births are far more frequent than Moclan society publicly admitted, and that an extensive network of adult Moclan females exist in hiding from the Moclan authorities. Among the unique aspects of Moclans' biology is that they urinate only once a year, with this event being of such significance that Moclans return to their home planet with those closest to them to urinate in a sacred spot chosen by each individual. Moclans also have strong jaws and digestive systems which allow them to eat almost anything, from any kind of meat and plants, to many types of metal and chemicals. Moclans reproduce by laying eggs, which must be incubated for 21 days by a parent. Moclus enjoys considerable political clout because it is a weapons manufacturer on which the Union depends.
Halston Sage as Lieutenant Alara Kitan (seasons 1–2, special guest star after "Home"):The Orville's young chief of security. Kitan is from Xelaya, a high-gravity planet that gives her greater-than-human strength in Earth gravity. She can knock down doors and walls, and crush a solid block of titanium or reshape it into a sphere with her bare hands. She receives the Sapphire Star for her role as acting commanding officer after Mercer and Grayson are abducted by the Calivon during Bortus's incubation of his egg. Sage departed the series in the third episode of the second season when her character resigned her post to be with her family on her home planet after it was discovered that she was losing her strength due to her long period away from her home planet's gravity, using the opportunity to reconnect with her parents.
J. Lee as Lieutenant (Lieutenant Commander after "New Dimensions") John LaMarr:The navigator of the Orville for most of the first season. He and Malloy strike up an immediate friendship in the first episode. Though intellectually gifted, he learned while growing up to hide his intelligence and settle for modest ambitions in order to fit in with his peers. When Grayson discovers his high aptitude in "New Dimensions", she encourages LaMarr to fulfill his potential. As a result, he acquits himself so well during that episode's crisis that he replaces the outgoing Lt. Commander Newton as the Orville's chief engineer.
Mark Jackson as Isaac:Named after Isaac Newton, and serving as the Orville's science and engineering officer, Isaac is a member of the artificial, non-biological race from Kaylon-1 that views biological lifeforms, including humans, as inferior. In the pilot episode, Isaac explains to Mercer that the Union's Admiralty offered a posting to any willing Kaylon, as an attempt to initiate relations between the two powers. Isaac accepted the offer as an opportunity to study human behavior. During the course of his time with the crew, he comes to observe and understand aspects of human behavior, such as relationships, sarcasm, slang, and practical jokes. Isaac perceives his surroundings with his body's internal sensors. His two glowing blue "eyes" are purely anthropomorphic, with Gordon once putting a Mr. Potato Head face on him without Isaac realizing it. After returning to Kaylon-1, the other Kaylon engage in a campaign of genocide against biological lifeforms; Isaac chooses to side with the Union and betray his own people. He later marries Doctor Claire Finn.
Jessica Szohr as Lieutenant Commander Talla Keyali (season 2–3):The ship's second Xelayan Chief of Security, who replaces Alara Kitan after her resignation in season 2. Like Kitan, she is from Xelaya, a high-gravity planet that gives her greater-than-human strength in Earth gravity.
Anne Winters as Ensign Charly Burke (season 3):The ship's second navigator who replaces John LaMarr after his promotion to chief engineer. She distrusts Isaac because her best friend Amanda, whom she was in love with, was killed during the Kaylon attack on Earth.
Norm Macdonald as Lieutenant Yaphit:A gelatinous engineering officer who develops a romantic interest in Doctor Finn. Recipient of the Sapphire Star medal for heroism during the Kaylon conflict.
