[5] Before Gatwa's casting was announced, several actors were heavily rumoured to be taking over from Whittaker, including Hugh Grant, Michael Sheen, Kris Marshall, Richard Ayoade, Michaela Coel, Kelly Macdonald, and Lenny Henry.

Russell T Davies' return as the programme's showrunner also led to speculation that an actor he had previously worked with in other projects would join him as the Fourteenth Doctor, with Olly Alexander, Lydia West, Omari Douglas, T'Nia Miller, and Fisayo Akinade ranking highly in bookies' odds.

[14][15] In an article released on the Doctor Who website, Gatwa said, "This role and show means so much to so many around the world, including myself, and each one of my incredibly talented predecessors has handled that unique responsibility and privilege with the utmost care.

Davies stated "the path to Ncuti's 15th Doctor is laden with mystery, horror, robots, puppets, danger and fun!

[20] One of them was an image of a "well-known American football player" wearing a "suit skirt"; though Downe thought they would have to "wait a bit of time" before introducing that, as it's "such a big jump from former Doctors.

[24] In the 2023 Christmas special "The Church on Ruby Road", the Doctor wears three different costumes; including a kilt and vest when dancing in a nightclub.

[26] Writing in British Vogue, Radhika Seth described the Fifteenth Doctor's early costumes as ranging "from a tangerine-coloured knit and a bright blue double-breasted pinstripe suit, to a glossy leather trench paired with a sweatshirt zipped down to expose his chest and a set of delicate gold necklaces, summarising that "Doctor Who is getting sexy".

In the original version, while preparing to film his regeneration scene, William Hartnell (David Bradley) looks across the TARDIS console and sees a vision of Matt Smith, the actor who played the then-incumbent Eleventh Doctor during the show's fiftieth anniversary year.

The two Doctors team up to defeat the malevolent deity the Toymaker (Neil Patrick Harris), and later use the remaining power of the latter's lingering reality-warping domain to duplicate the TARDIS.

The Fifteenth Doctor shares some words of wisdom with his predecessor, who returns the favour by wishing him luck, before setting off for new adventures in his version of the TARDIS.

In the subsequent episodes, the Doctor and Ruby encounter a surprising amount of magical and supernatural threats, including a fairy circle in "73 Yards" and Maestro (Jinkx Monsoon), the child of the Toymaker, in "The Devil's Chord".

Late in the season, the Doctor begins a romance with a time and space travelling male bounty hunter known as Rogue (Jonathan Groff) in the episode of the same name.

[28] Over the course of the season, the Doctor and Ruby repeatedly encounter the same woman's likeness (played by Susan Twist) across time and space, which they first begin to notice in "Dot and Bubble".

At the 2022 Paris Fan Festival, Matt Smith, who portrayed the Eleventh Doctor, openly expressed his support to Gatwa taking on the role.

[38] Mary McNamara of Los Angeles Times called Gatwa "an absolute delight" and wrote that his "unbridled exuberance makes this an easy sell and serves as a data bridge between new viewers and old.