A job was the task an individual did on a daily basis.
The Doctor
The Eleventh Doctor claimed that he would be brilliant at having a job. He considered his duties as UNIT's scientific advisor to be his job, though Clara Oswald doubted that he could ever hold a job. (TV: The Day of the Doctor [+]Steven Moffat, 50th Anniversary Specials (BBC One, 2013).)
Across their many incarnations, the Doctor held various jobs, usually for the purposes of their investigations. The Tenth Doctor took a job as a teacher to investigate the oddities at Deffry Vale High School. (TV: School Reunion [+]Toby Whithouse, Doctor Who series 2 (BBC One, 2006).) The Eleventh Doctor briefly held a job at Sanderson & Grainger, a department store in Colchester. Though he claimed he did so to "live in the moment", he was actually investigating Cyber-activity which seemed to be localised around his new workplace. (TV: Closing Time [+]Gareth Roberts, Doctor Who series 6 (BBC One, 2011).) The Twelfth Doctor worked as a lecturer at St Luke's University since the 1940s (AUDIO: Regeneration Impossible [+]Alfie Shaw, Short Trips (Big Finish Productions, 2020).) as he and Nardole guarded the Vault. In 2017, he took on the additional job of being Bill Potts' personal tutor. (TV: The Pilot [+]Steven Moffat, Doctor Who series 10 (BBC One, 2017).) When a Weeping Angel sent the Twelfth Doctor back to Sto to 1917 from 2017, the Doctor eventually got a job at Max Capricorn Cruiseliners, using its resources to help smuggle discriminated against cyborgs off-world. (COMIC: A Confusion of Angels [+]Error: Code 2 - no data stored in variables, cache or SMW.) As part of their investigations of Kerb!am, the Thirteenth Doctor and Team TARDIS briefly took on jobs at the company. (TV: Kerblam! [+]Pete McTighe, Doctor Who series 11 (BBC One, 2018).)
In an alternate timeline caused by a temporal collision, the First Doctor spent three months working as a guest lecturer at a university in Kiria City on Urbinia. (AUDIO: Daughter of the Gods [+]David K Barnes, The Early Adventures (Big Finish Productions, 2019).)
The Doctor's companions
The Doctor's first two human companions, Ian Chesterton and Barbara Wright, were teachers at Coal Hill School, teaching science and history respectively. (TV: An Unearthly Child [+]Anthony Coburn, adapted from The Pilot Episode (Anthony Coburn), Doctor Who season 1 (BBC tv, 1963).) By 2010, the two were employed at the University of Cambridge. (TV: Death of the Doctor [+]Russell T Davies, The Sarah Jane Adventures series 4 (CBBC, 2010).) Liz Shaw also taught at Cambridge. (AUDIO: Primord [+]Error: Code 2 - no data stored in variables, cache or SMW.)
In an alternate timeline caused by a temporal collision, Steven Taylor spent three months working at a spaceport in Kiria City on Urbinia. (AUDIO: Daughter of the Gods [+]David K Barnes, The Early Adventures (Big Finish Productions, 2019).)
Sarah Jane Smith worked as a journalist. (TV: The Time Warrior [+]Robert Holmes, Doctor Who season 11 (BBC1, 1973-1974).)
Prior to her travels with the Doctor, Rose Tyler worked as a shop girl in Henrik's before the Ninth Doctor blew up the building. Before she could find a new job, she joined the Doctor in his travels. (TV: Rose [+]Russell T Davies, Doctor Who series 1 (BBC One, 2005).) During their investigation of Deffry Vale High School, Rose was forced to work as a lunchlady. (TV: School Reunion [+]Toby Whithouse, Doctor Who series 2 (BBC One, 2006).)
When the Doctor and Martha Jones were stranded in 1969, the latter was forced to work at a shop. (TV: Blink [+]Steven Moffat, adapted from What I Did on My Christmas Holidays by Sally Sparrow (Steven Moffat), Doctor Who series 3 (BBC One, 2007)., COMIC: A Little Help from My Friends [+]Jody Houser, Doctor Who: The Thirteenth Doctor (Titan Comics, 2020).) After leaving the TARDIS, Martha was employed by UNIT. (TV: Reset [+]J. C. Wilsher, Torchwood series 2 (BBC Three, 2008).) Some time after the Planetary Relocation Incident, she left UNIT to become a freelance alien hunter alongside Mickey Smith. (TV: The End of Time [+]Russell T Davies, Doctor Who Christmas Special 2009 and New Year Special 2010 (BBC One, 2009-2010).)
Donna Noble's career consisted mainly of temp jobs. (TV: The Doctor's Daughter [+]Stephen Greenhorn, Doctor Who series 4 (BBC One, 2008).) After leaving the Doctor, Donna had taken a new job in 2009, one that Wilfred Mott felt did not pay enough to ensure her financial independence. (TV: The End of Time [+]Russell T Davies, Doctor Who Christmas Special 2009 and New Year Special 2010 (BBC One, 2009-2010).) Some years after her travels with the Doctor, she lost a job after spilling coffee onto a computer. (TV: The Star Beast [+]Russell T Davies, adapted from Doctor Who and the Star Beast (Pat Mills and John Wagner), Doctor Who 60th Anniversary Specials (BBC One and Disney+, 2023).) Upon her memories of her time with the Doctor being restored, Donna was employed by UNIT. (TV: The Giggle [+]Russell T Davies, Doctor Who 2023 specials (BBC One, 2023).)
Amy Pond held multiple jobs during her time travelling with the Eleventh Doctor. She initially worked as a kissogram, (TV: The Eleventh Hour [+]Steven Moffat, Doctor Who series 5 (BBC One, 2010).) before changing jobs to become a model, (TV: Closing Time [+]Gareth Roberts, Doctor Who series 6 (BBC One, 2011)., Asylum of the Daleks [+]Steven Moffat, Doctor Who series 7 (BBC One, 2012).) a writer for a travel magazine (TV: The Power of Three [+]Chris Chibnall, Doctor Who series 7 (BBC One, 2012).) and finally a fiction author. (TV: The Angels Take Manhattan [+]Steven Moffat, Doctor Who series 7 (BBC One, 2012)., The Bells of Saint John [+]Steven Moffat, Doctor Who series 7 (BBC One, 2013).) By contrast, her husband Rory Williams kept his job as a nurse throughout his tenure as a companion. For his part, the Doctor was shocked that both of them had jobs, having assumed that the couple mainly kissed when he was not there. (TV: The Power of Three) By one account, Rory became a full medical doctor after being separated from the Doctor. (COMIC: Imaginary Enemies [+]Error: Code 2 - no data stored in variables, cache or SMW.)
Clara Oswald initially worked as a nanny, (TV: The Bells of Saint John [+]Steven Moffat, Doctor Who series 7 (BBC One, 2013).) before she became a teacher at Coal Hill School. (TV: The Day of the Doctor [+]Steven Moffat, 50th Anniversary Specials (BBC One, 2013).) She later transferred to Ravenscaur School. (TV: Clara Oswald and the School of Death [+]Robbie Morrison, Doctor Who: The Twelfth Doctor (Titan Comics, 2016).) Not long after the Eleventh Doctor's regeneration, Clara noted to the Twelfth Doctor that their travels were her hobby, not her job. (TV: Into the Dalek [+]Phil Ford and Steven Moffat, Doctor Who series 8 (BBC One, 2014).)
Yasmin Khan was a police officer employed at Hallamshire Police when she met the Thirteenth Doctor. (TV: The Woman Who Fell to Earth [+]Chris Chibnall, Doctor Who series 11 (BBC One, BBCA, Space and Australian Broadcasting Corporation, 2018).) Though she was initially heavily dedicated to her profession, to the point that her family considered her to be "married to her job", (TV: Arachnids in the UK [+]Chris Chibnall, Doctor Who series 11 (BBC One, 2018).) her increasing association with the Doctor caused her to she leave this profession sometime before the First Flux event. (TV: The Halloween Apocalypse [+]Chris Chibnall, Doctor Who series 13 (BBC One and BBC America, 2021).)
Graham O'Brien was once employed as a bus driver, but had retired prior to becoming a companion of the Thirteenth Doctor. (TV: The Woman Who Fell to Earth [+]Chris Chibnall, Doctor Who series 11 (BBC One, BBCA, Space and Australian Broadcasting Corporation, 2018)., Rosa [+]Malorie Blackman and Chris Chibnall, Doctor Who series 11 (BBC One, 2018).)
Others
Lavinia Smith was a world-renowned virologist in the late 20th century. (TV: The Time Warrior [+]Robert Holmes, Doctor Who season 11 (BBC1, 1973-1974).)
In 2008, Tish Jones got a PR job at Lazarus Laboratories, (TV: The Lazarus Experiment [+]Stephen Greenhorn, Doctor Who series 3 (BBC One, 2007).) which was secretly arranged by the Saxon Master. Later, having been "phoned up" "out of the blue", Tish got a job at 10 Downing Street on the Master's first day as Prime Minister of the United Kingdom. (TV: The Sound of Drums [+]Russell T Davies, Doctor Who series 3 (BBC One, 2007).)