Jacob Fosie (1679 – 1 December 1763) was a Danish artist, watercolor painter, etcher, engraver, organist and author.

He painted landscapes in watercolor, mostly in the style of Dutch masters.

Among the frequent guests were the artists Johan Martin Preisler, Gustav de Lode and Michael Keyl, the painters Johan Hörner and Carl Gustaf Pilo, the sculptor Simon Carl Stanley, the poet Christian Frederik Wadskiær and several other writers.

Fosie was a wealthy man; he busied himself with mechanics and linguistics, and was for several years organist at the Church of Holmen and as such undoubtedly an accomplished musician, although he once admitted that he was not practicing music outside of Sundays.

Nevertheless, he was at home in all the major languages, as well as Latin culture, possessed a large and good library, and was highly regarded for his multifaceted skills and knowledge.