Logan

James Howlett / Logan: A former member of the X-Men and a physically enhanced mutant with accelerated healing. Charles Xavier's former pupil and Laura's biological father, dealing with his age and ailment. He is one of Charles Xavier's caregivers, alongside Caliban. Mangold spoke of Logan's age influencing his regenerative capabilities, which he stated may no longer produce soft skin, "so we imagined he heals quickly, still, but it leaves a scar. The simple idea was that his body would start to get a little more ravaged with a kind of tattooing of past battles, lacerations that remain of previous conflicts." On the second page of the screenplay, Mangold spoke of Logan as "... he's older now and it's clear his abilities aren't what they once were. He's fading on the inside and his diminished healing factor keeps him in a constant state of chronic pain—hence booze as a painkiller." In 2015, Jackman requested fan input for the direction Wolverine's story should go in the next film while seeming to confirm that the project would serve as his farewell to Logan. To prepare for his role, Jackman ate a minimum of six meals per day when working with trainer Mike Ryan. Ryan stated that an average workout session for Jackman lasts up to three hours, beginning at 4:00 a.m. Jackman stated, "It's going to be very different. Very different in tone and hopefully different to anything we've done." Regarding the more personal tone, Jackman noted, "That's always been really his dilemma, coming to terms with who he is". Jackman has also explained that comedian Jerry Seinfeld was indirectly responsible for his decision to stop playing Logan after 17 years, with Jackman stating, "I was having a chat with [Seinfeld] about a year ago ... he was talking about why he finished Seinfeld ... He said he'd always had this feeling and belief that you never know when either your energy or the audience's energy is going to dip over into people [saying] 'Oh, please go.'" Jackman accepted a pay reduction to ensure that the film would be produced to receive an R-rating. Additionally, Jackman portrays Logan's clone, X-24.

Hugh Jackman

Charles Xavier: A mutant who is the world's most powerful telepath, the founder and former leader of the now-defunct X-Men and formerly known as Professor X. Charles's telepathic abilities have become unstable due to age (over 90 years) and an unknown brain disease, and at times, he does not recognize Logan. During the events of Logan, Xavier is cared for by Logan and Caliban. Regarding Xavier and the themes of aging and loneliness, Mangold said, "We've seen these characters in action, saving the universe. But what happens when you're in retirement and that career is over? ... The really interesting thing to me, or a place to dig that hadn't been dug, was the idea of mutants when they're no longer useful to the world, or even sure if they can do what they used to do. Their powers are diminished like all of ours are by age ... Our Charles is a very sweet character in this film. I think he's always been an incredibly sweet character. With the addition of his own physical fragility in this movie, he becomes an incredibly powerful paternal figure in the movie. Logan is more of a reluctant one, I think you can easily guess." Stewart remarked that "... this is probably the end of this franchise for me. But the thing about science fiction and fantasy is that you can never, ever say it's the end, it's over."

Patrick Stewart

Laura / X23: A mysterious young girl, who is "very much" like Logan as well as Logan's biological daughter. She is also subject "X-23". On Keen's portrayal of Laura, Mangold mentioned, "If anyone could steal a movie from [Jackman], it would be Dafne. She carries, all the time, a slight strangeness." In an interview with Digital Spy, Mangold stated, "... [Keen] was 11 years old when we were shooting. She's a remarkable kid. Her parents are actors, and she's kind of a very modern kid. Very physically capable. Incredibly gifted as an actress. I mean, it was a huge risk for Fox to allow me to make a movie where the third point of the triangle was built upon someone so young." Mangold stated that the worldwide search for an actress to portray Laura was one in which he was seeking "someone who was bilingual because I wanted a Latina kid—one who was between 10 and 12, and was a credible child." He later stated of Laura that: "She's an 11-year-old girl equipped with all the volatility, instability, mood swings, shadows and potential violence of our hero." Co-writer Scott Frank pushed for the character to speak as little as possible when he joined the project to avoid making her into a typical kid sidekick, explaining, "I read a few other drafts of the script that Jim worked on, and in all those drafts she was talking from the beginning and had an attitude. I thought that was a giant mistake." 11-year-old Nayah Murphy served as Dafne's stunt double. Millie Bobby Brown auditioned for the role before Keen was cast. Logan was Keen's film debut.

Dafne Keen

Donald Pierce: Transigen's relentless, calculating, and intense head of security and leader of the militant Reavers, who is sent to retrieve Laura, which brings him into conflict with Wolverine. Holbrook said of the character, "He's an innovative engineer and he's a big fan of Wolverine. He just wants to hang out with him ... There's a lot of surprising stuff in it." Mangold praised Holbrook's performance, saying that "[he] is just a fabulous actor. I wanted this film to feel intimate and real and truthfully acted, and I wanted very much to break away from the kind of bloated feeling I've gotten from a lot of comic-book movies."

Boyd Holbrook

Caliban: An albino mutant who can sense and track other mutants, who is helping Logan take care of Xavier. On Merchant taking the role, Mangold mentioned, "I'm always interested to find the thing that looks most interesting on the actors. Stephen is a huge man. One of the things that is so wonderful filming with him for a character like this is that he's a good six inches taller than Logan, and huge over Patrick. The little kid in the movie would come up to basically his knee. So there's a wonderful sense of scale—but he has heart too." Mangold concluded by stating, "... So that was a wonderful energy to enter the movie, and someone who instead of turning things into their own energy kind of joined ours." A younger Caliban was previously portrayed by Tómas Lemarquis in X-Men: Apocalypse.

Stephen Merchant

Dr. Zander Rice: The surgical head of Transigen, whose father was killed by Logan during his escape from the Weapon X Headquarters at Alkali Lake. On the character of Rice, Mangold stated, "He's the puppet master behind Pierce and the Reavers, and has a much larger role in the sense that he's actually the kind of brilliant mind that is trying to grow mutants."

Richard E. Grant