Vishniac (Romanian: Вишняк) could refer to:
Roman Vishniac (1897-1990), a Russian-American, Jewish, photographer and biologist.
Wolf V. Vishniac (1922-1973), an US microbiologist who died during an expedition to Antarctica.
Vishniac, a crater on Mars, named after Wolf V. Vishniac.
Ethan T(ecumseh). Vishniac, an US astrophysicist, and editor of the Astrophysical Journal.
Ostriker-Vishniac effect
