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 (DW: The Girl in the Fireplace)
 * Kathy (DWS: Corner of the Eye)
 * Catherine (MA: Who Killed Kennedy)

As first name

 * Cath Lloyd (DWM: F.A.Q.)
 * Catherine Broome (TN: Companion Piece)
 * Catherine Harries (EDA: The Banquo Legacy)
 * Catherine de Medici (DW: The Massacre of St Bartholomew's Eve)
 * Cathy Salt (DW: Boom Town)
 * Kath McDonnell (DW: 42)
 * Katharine Delbane (PDA: Heart of TARDIS)
 * Kathleen Dudman (DW: The Curse of Fenric)
 * Kathy Beale (DW: Dimensions in Time)
 * Kathy Nightingale (DW: Blink)
 * Kathy Swanson (TW: They Keep Killing Suzie)

As place name

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

Regular

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

Guest

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

Featured

 * Catherine Bailey, who played Miss Wyckham in SJA: Lost in Time.
 * Catherine Cusack, who played the Blue Kang Leader in DW: Paradise Towers.
 * Catherine Howe, who played Ara in DW: The Underwater Menace.
 * Catherine Schell, who played Countess Scarlioni in DW: City of Death.
 * Cathy Tucker, who played Melaina in K9TV: Sirens of Ceres.
 * Katherine Burford, who played the Nurse in DW:The Wedding of River Song.
 * Katherine Schofield, who played Sabetha in DW: The Keys of Marinus.
 * Kathryn Drysdale, who played Bliss in DW: Love & Monsters.
 * Kathryn Ludlow, who played the Little Girl in DW: The Greatest Show in the Galaxy.

Extra

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

Vocal

 * Catherine Fleming, who provided the voice of the Animus in DW: The Web Planet.
 * Catherine Harvey, who voiced Panthea Vyse in BFA: The Diet of Worms, Glory Days, and Absence.
 * Katherine Parkinson, who voiced engineer Danika Meanwhile, in BFA: 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 DW: The Mark of the Rani and The Two Doctors.

Writers

 * Catherine Tregenna, a Torchwood television writer.

Other

 * Catherine Childs, an Assistant Floor Manager for DW: 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 DW: Evolution of the Daleks.

Prose

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