John Whiteside FRS (1679 – 12 October 1729) was an English chaplain, museum curator, experimental philosopher, and astronomer.

He was the chaplain at Christ Church, Oxford, and the Keeper (head) of the Ashmolean Museum from 14 December 1714 until his death on 12 October 1729.

In his role as Keeper of the Ashmolean Museum, he bought new scientific equipment at his own expense, creating a large collection of apparatus, including a clock made by George Graham (1673–1751), the inventor of the mercury compensation pendulum.

Whiteside worked on recreating and augmenting the museum's fossil collection, accepting specimens provided by the Master of University College, Arthur Charlett.

[4] The only known depiction of Whiteside is in an etching/engraving of the tavern Antiquity Hall Suburbanum Oxon (c.1720), where he is satirised due to his antiquarian interests by the engraver George Vertue (1684–1756).