John Charles Mason (1798–1881) was a British East India Company servant and marine secretary to the Indian government (home establishment).
His grandfather, Charles Mason, served with distinction in the expedition to Guadeloupe in 1758–9, and with the allied army in Germany in 1762 and in 1793–6.
For three years he served in the office of Dunn, Wordsworth, & Dunn, solicitors, 32 Threadneedle Street, till in April 1817 he received an appointment in the secretary's office at the East India House on the ground of his father's services—a unique episode in the history of the company's patronage.
From 1817 to 1837 he was almost wholly employed upon confidential duties under the committee of secrecy—namely, in 1823 in negotiating a treaty with the government of the Netherlands for the cession of the settlement in the Straits of Malacca to the Dutch; in 1829 in arranging the secret signals for the East India Company's ships; in 1833 in negotiating for the renewal of the company's charter; and in 1834 in the parliamentary inquiry upon matters connected with China.
In accordance with that committee's report of 1867, the Crocodile, Euphrates, Jumna, Malabar, and Serapis were constructed as troop-ships to convey troops to and from India.