Grigory Silovich Ostrovsky (1756–1814) was a Russian painter active during the eighteenth century.
Almost nothing is known of Ostrovsky's life, and little is known about his career; the only paintings which can be definitively traced to him are 17 signed and dated portraits which were discovered in the 1970s. All paintings were made in 1770s-1780s and come from the Neronovo estate, located in about 25 km SE of Soligalich. In the eighteenth century this belonged to the Cherevin family, and most of the portraits are of members of the family. Stylistically, the paintings appear to be the work of an itinerant painter; there is a possibility, too, that he may have studied icon painting. Presumably, Ostrovsky originally was from Veliky Ustyug.
Ostrovsky's paintings are currently held by the Soligalich Regional Studies Museum in Soligalich.