Belinda Chandra is a fictional character in the British science fiction television series Doctor Who, portrayed by Varada Sethu. The character was created by Doctor Who showrunner Russell T Davies. In the show's fifteenth series, Belinda serves as the companion to the Fifteenth Doctor (Ncuti Gatwa), an incarnation of the alien time traveller known as the Doctor. Debuting in the 2025 episode "The Robot Revolution", Belinda is initially kidnapped by robots from another planet, and after the Doctor saves her, the pair find they cannot return to her home time period on Earth. She travels with the Doctor to use a device called the Vindicator in order to return home. She eventually returns home but is trapped within a heteronormative alternate reality created by the Doctor's enemy The Rani, in which Belinda has had a daughter named Poppy with the Doctor. After Poppy is removed from the timeline alongside the reality, the Doctor restores Poppy to the timeline as Belinda's daughter, and she remains on Earth to care for her.

Sethu had previously portrayed the character Mundy Flynn in the 2024 episode "Boom". Davies was impressed with Sethu's performance and after discussion with the production team, she was offered the role of Belinda without needing to audition. Unlike other companions in the series, Belinda was portrayed as someone who did not want to partake in the Doctor's adventures and wishes to return home, providing friction between the two characters.

Belinda received a positive response for her appearance in her debut episode, "The Robot Revolution", with many critics positively highlighting her unique dynamic with the Doctor. The conclusion of her arc and her role in the season finale, "The Reality War", was criticised by critics, with many feeling that Belinda was "wasted" as a character.

Doctor Who is a long-running British science-fiction television series that began in 1963. It stars its protagonist, The Doctor, an alien who travels through time and space in a ship known as the TARDIS, as well as their travelling companions. When the Doctor dies, they can undergo a process known as "regeneration", completely changing the Doctor's appearance and personality. Throughout their travels, the Doctor often comes into conflict with various alien species and antagonists.

Belinda first appears in the 2025 episode "The Robot Revolution". Several years before the episode's events, she received a star diploma from her ex-boyfriend, Alan Budd (Jonny Green). This diploma resulted in a planet orbiting the star to be dubbed "Missbelindachandra One". In May 2025, she works as a nurse and lives in a sharehome. Robots from Missbelindachandra One kidnap her and take her to the planet, dubbing her the Queen of the planet. They attempt to marry her to the "AI Generator", the overlord of the planet, but the Fifteenth Doctor (Ncuti Gatwa) saves her. The pair are recaptured, and it is revealed the Generator is actually Alan, who had been kidnapped by the robots many years prior. Belinda and the Doctor work together to stop Alan, and prepare to leave. The Doctor, remembering her descendant Mundy Flynn, who he worked with in the far future (as seen in the 2024 episode "Boom"), attempts to get her to travel with him, but she rejects him and insists he take her home. The Doctor obliges but cannot return to the time period from which Belinda hailed. In the following episode, "Lux" (2025), the Doctor constructs a device called the Vindicator, which will allow them to return to May 2025 when enough locations across time and space have been visited. The following episodes depict the Doctor and Belinda travelling across the universe to gain enough energy on the Vindicator to return home.

The Vindicator eventually gathers enough energy to return home at the end of "The Interstellar Song Contest" (2025), but the pair wind up trapped in an alternate, heteronormative reality created by the Doctor's enemy The Rani (Archie Panjabi and Anita Dobson). The Doctor and Belinda are reimagined in this reality as a married couple who have an infant daughter named Poppy (Sienna-Robyn Mavanga-Phipps), with no memories of their old lives. The Doctor is eventually able to recover his memories and also restores Belinda's. When he goes to confront the Rani and dispel the altered reality, Belinda is placed inside of a special room alongside Poppy in order to prevent Poppy from being erased when the reality is dispelled. When reality is restored, Poppy is still erased from both of their memories, but after the Doctor is reminded of Poppy's existence, he causes a regeneration in the time vortex. This results in reality changing to have Belinda be Poppy's mother, but not the Doctor's child. Belinda stays behind to care for Poppy while the Doctor departs to regenerate.

Belinda, outside of the television series, also appears in comic strips published by Titan Comics, as well as in several novels.

Varada Sethu was announced to be portraying a new companion in Doctor Who's fifteenth series in April 2024, though the character she was playing was not announced prior to the 2024 San Diego Comic-Con, where the character's name was confirmed. Prior to Sethu's appearance as Belinda, she appeared as the character Mundy Flynn in the 2024 episode "Boom"; this episode aired after she had been confirmed as a companion, and her appearance in "Boom" was not confirmed prior to the episode's airing. The relationship between Flynn and Belinda was not established in the episode, leading to speculation of the two characters' relation. Prior to Flynn's appearance, the concept of a companion's actor appearing as different characters prior to the companion's introduction had previously been done with Clara Oswald (Jenna Coleman) in the show's seventh series.