Isaac

 has several meanings pertinent to the Doctor Who universe and the 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

 * Isaac (Bunker Soldiers) (PDA: Bunker Soldiers)
 * Isaac (An Overture Too Early) (ST: An Overture Too Early)
 * Isaac (A Town Called Mercy) (DW: A Town Called Mercy)

As first name

 * Isaac Ashdown (PDA: The Roundheads)
 * Isaac Barclay (BFA: Plague of the Daleks)
 * Isaac Dobbs (EDA: The Burning)
 * Isaac Newton (BFA: Summer, et al)
 * Isaac Penley (NA: Christmas on a Rational Planet)
 * Isaac Summerfield (NA: Return of the Living Dad, et al)
 * Isaac Greatorex (BBV: Ghosts of Winterbourne)

As first name

 * Isaac Stephen Montgomery, who played the Stern Soldier in TW: The Middle Men

As surname

 * Jeffrey Isaac, who played Khepren in DW: The Daleks' Master Plan
 * Robyn Isaac, who played Linda in TW: Random Shoes

Cameramen

 * Isaac Che who was key grip for Torchwood
 * Mark Isaac, who was a focus puller for Doctor Who