John Charles Melliss (23 January 1835 – 23 August 1911) was a notable British engineer and amateur naturalist.
He was born on the island of St Helena in the South Atlantic Ocean. His father, Lieutenant G.W. Melliss, was an officer of the St Helena Artillery. After training as an engineer, and serving as an officer in the Royal Engineers, he was appointed as government surveyor in St Helena from 1860-1871. In 1871, because of government cutbacks, he was made redundant and returned to London, where he subsequently formed the firm of J.C. Melliss and Co.
In 1875, he published the work for which he is best known: "St. Helena: A Physical, Historical and Topographical Description of the Island, including the Geology, Fauna, Flora and Meteorology".
Joseph Dalton Hooker named the genus Mellissia in his honour.
To commemorate the book's centenary in 1975, the St. Helena Post Office published a series of stamps.
Melliss's son, H.J. Melliss, joined his father's company (later named "Melliss and Partners" following a partnership with H.R. Smart). He worked for the company until 1955.