Johan Jacob Bruun (30 November 1715 – 4 January 1789) was a Danish painter.
Often working in gouaches, he is most known for his topographic prospects which herald the development of a Danish landscape painting.
He started in an apprenticeship under the painter Johan Herman Coning and taught miniature painting.
Between 1737 and 1769 he executed more than 1,000 gouaches, watercolours and touch drawings depicting towns, castles and other motives.
He assisted with Lauritz de Thurah's Hafnia Hodierna (1746) and Den Danske Vitruvius (1746–49).