Name
- Hickes, Gaspar al. Jasper, Captain; RN1
- Hill, Richard, diplomatist1
- Hodges, William, 1st Baronet1
- Hoffmann, Johann Philipp, Imperial Resident in London1
- Howard, Charles, 3rd Earl of Carlisle1
- Hyde, Edward, 3rd Earl of Clarendon1
- Jackson, Robert, Resident at Stockholm1
- Janua, Christophorus1
- Jennings, John, Admiral; Lord of the Admiralty and Governor of Greenwich Hospital1
- Jeronimus, of Rome1
- Joannes Isaacus, called Hollandus1
- Johannes, Scriptor1
- John William Friso, Prince of Orange; Prince of Nassau-Dietz, Stadtholder of Friesland and Groningen1
- Johnson, Henry, MP1
- Jones, James, Colonel; 38th Foot1
- Jones, Robert, Churchwarden of St Bride's, Fleet St1
- Joseph I, Emperor of Germany1
- Joveninus, Frater, of Rome1
- Jābir ibn Ḥayyān, alchemist, 9th century-10th century1
- Kelley, Edward, Alchemist1