John Giles Eccardt was a German-born British portrait painter.
He came to England in the company of the French painter Jean-Baptiste van Loo for whom he worked as an assistant. When Van Loo departed the country, Eccardt remained and set up a portrait-painting business. He died in 1779.
In the following years he did portraits of a number of leading members of British society including twenty six of his chief patron Horace Walpole.