Olga Romanoff: Or, the Syren of the Skies: A Sequel to "The Angel of the Revolution". Is a science fiction novel by the English writer George Griffith.

Olga Romanoff is the sequel to The Angel of the Revolution (1893) and set 125 years later. The novel describes the upheaval which transforms this Utopian state to one of total anarchy.

Both Olga Romanoff and the prequel The Angel of the Revolution are remarkable for their foresight of battle tactics in air warfare and for their anticipation of radar, sonar and nuclear weapons. They include elements which would only later become commonplace, notably the struggle by international cartels for world domination and the apocalyptic visions of Armageddon on Earth and of disaster from the heavens by a comet.

The Syren of the Skies appeared in Pearson's Weekly in 1893-1894 and was published in book form as Olga Romanoff in 1894.

George Griffith (1857–1906), was one of the most influential British writers of science fiction and noted explorer, who wrote during the late Victorian and Edwardian age. Griffith was extremely popular in the United Kingdom, though he failed to find similar acclaim in the United States, in part due to his revolutionary and socialist views. A journalist, rather than scientist, what his stories lack in scientific rigor and literary grace, they make up for in sheer exuberance of execution.