Gaspar Fagel (25 January 1634 – 15 December 1688) was a Dutch politician, jurist, and diplomat who authored correspondence from and on behalf of William III, Prince of Orange, during the English Revolution of 1688.

After the resignation and subsequent murder of Johan and Cornelis de Witt in 1672, Fagel was elevated to the position of Grand Pensionary.

He was distinguished for his integrity and the firmness with which he repelled the attempts of Louis XIV of France against his country, and for his zeal in supporting the claims of William III, Prince of Orange to the English throne.

[1] In 1687, James Stewart, a Scottish Presbyterian lawyer who supported repeal of the Test Acts, had been in contact with a number of Dutch acquaintances.

[3] Many dissenters viewed the act as essential for guaranteeing the primacy of the Protestant faith and Fagle confirmed the Dutch would support the softening of some laws only if: "... those Laws remain still in their full vigour by which the Roman Catholics are shut out of both Houses of Parliament, and out of all public employment; Ecclesiastical, Civil and Military: as likewise all those others, which confirm the Protestant Religion and which secures it against all the attempts of the Roman Catholic.