Sydney J. van Scyoc (born July 27, 1939) is an American science fiction writer. Her first published story was "Shatter the Wall" in Galaxy in 1962. She continued to write short stories throughout the 1960s and in 1971, published her first novel, Saltflower. Other novels followed until 1992, when she abandoned writing to make and sell jewelry. Retired now, she gardens and has begun to write science fiction again.
According to book reviewer Dani Zweig , coming of age and human evolution are common themes in Scyoc's books. For example, in Assignment Nor'Dyren, the two main characters are young humans off on an adventure visiting an alien world. Tollan Bailey has not been able to fit into the post-industrial work force of Earth, but the world Nor'Dyren provides an environment well suited to his interests. Laarica Johns is the other main human character, struggling to develop a career and escape from her over-protective parents. The theme of evolution is also present in Assignment Nor'Dyren, with questions raised about how human-like species must adapt to an environment that includes advanced technologies such as space travel.