Eustachius

Eustachius may refer to:


 * Variant of the name Eustathius


 * Saint Eustachius
 * Sint Eustatius, Dutch island in the Caribbean
 * Bartolomeo Eustachi (c. 1500–1510 – 1574), anatomist
 * Eustáquio van Lieshout (1890–1943), Dutch missionary in Brazil
 * Eustachius Kugler, beatified German religious
 * Eustochius, fifth bishop of Tours from 443 to 460
 * Eustathius, son of Macrobius