Ethan Tecumseh Vishniac (born 1955) is an American astrophysicist. He is the son of microbiologist Wolf V. Vishniac, and grandson of photographer Roman Vishniac. He is the Editor-in-Chief of the Astrophysical Journal and a professor of Astronomy at Johns Hopkins University in Baltimore, after holding positions at University of Saskatchewan in Saskatoon, McMaster University in Hamilton, Ontario, Canada, and University of Texas in Austin. His wife Ilene Busch-Vishniac, the ninth president of the University of Saskatchewan (2012-2014), was previously Dean of the Faculty of Engineering at Johns Hopkins, and provost and vice-president (academic) of McMaster University from 2007 until 2012.