Katherine

 occurs several times in the Doctor Who universe and the relevant real world. They are listed below in alphabetical order by surname. If no surname is available, alphabetization occurs by the disambiguation term — that is, the bit between the parentheses in a title like Waitress (Random Shoes).

As only name

 * Katherine (TV: The Girl in the Fireplace)
 * Kathy (PROSE: Corner of the Eye)
 * Kathy (TV: Into the Dalek)
 * Catherine (PROSE: Who Killed Kennedy)

As first name

 * Cath Lloyd (COMIC: F.A.Q.)
 * Catherine Broome (PROSE: Companion Piece)
 * Catherine Harries (PROSE: The Banquo Legacy)
 * Catherine de Medici (TV: The Massacre of St Bartholomew's Eve)
 * Cathy Salt (TV: Boom Town)
 * Kath McDonnell (TV: 42)
 * Katharine Delbane (PROSE: Heart of TARDIS)
 * Kathleen Dudman (TV: The Curse of Fenric)
 * Kathy Nightingale (TV: Blink)
 * Kathy Swanson (TV: They Keep Killing Suzie)

As place name

 * The Glen of St Catherine (TV: Tooth and Claw)

Non-DWU material

 * Kathy Beale (NOTVALID: Dimensions in Time)

Regular

 * Catherine Tate, who played Tenth Doctor's companion, Donna Noble

Guest

 * Katherine Jenkins, who played Abigail Pettigrew and sang her song in TV: A Christmas Carol.

Featured

 * Catherine Bailey, who played Miss Wyckham in SJA: Lost in Time.
 * Catherine Cusack, who played the Blue Kang Leader in TV: Paradise Towers.
 * Catherine Howe, who played Ara in TV: The Underwater Menace.
 * Catherine Schell, who played Countess Scarlioni in TV: City of Death.
 * Cathy Tucker, who played Melaina in TV: Sirens of Ceres.
 * Katharine Burford, who played the Nurse in TV:The Wedding of River Song.
 * Katherine Schofield, who played Sabetha in TV: The Keys of Marinus.
 * Kathryn Drysdale, who played Bliss in TV: Love & Monsters.
 * Kathryn Ludlow, who played the Little Girl in TV: The Greatest Show in the Galaxy.

Extra

 * Catherine Olding, who played the young woman in NOTVALID: Attack of the Graske and one of the Couple in the Car in TV: From Out of the Rain.
 * Catherine York, who played a newsreader in TV: Turn Left.
 * Cathy Murphy, who played a Mum in TV: The Christmas Invasion.
 * Kathleen Bidmead, who played a woman in TV: Survival.
 * Kathryn Howard, who played a Woman in shop in TV: Ghost Machine.
 * Kathy Wolff, who played a Dancer in TV: The Masque of Mandragora.

Vocal

 * Catherine Fleming, who provided the voice of the Animus in TV: The Web Planet.
 * Catherine Harvey, who voiced Panthea Vyse in AUDIO: The Diet of Worms, Glory Days, and Absence.
 * Katherine Parkinson, who voiced Danika Meanwhile in AUDIO: The Death Collectors.

Directors

 * Catherine Morshead, the director of DW: Amy's Choice and The Lodger

make-up

 * Cathy Davies, a make-up artist for the Doctor Who stories The End of Time and Closing Time.
 * Catherine Davies, who provided the Make-Up for TV: The Mark of the Rani and The Two Doctors.

Writers

 * Catherine Tregenna, a Torchwood television writer.

Other

 * Catherine Childs, an Assistant Floor Manager for TV: An Unearthly Child, Marco Polo and The Daleks' Master Plan (with Caroline Walmsley).
 * Catherine Samuel, a production buyer and later a props buyer for Doctor Who.
 * Kath Blackman, an assistant production accountant during series 1 and 2 of BBC Wales Doctor Who.
 * Katherine Archer, a standby propsman for Doctor Who.
 * Katherine Lewis, a credited Cyfle trainee on TV: Evolution of the Daleks.

Prose

 * Kathryn Sullivan, the writer of The Diplomat's Story.