Eigen

Eigen may refer to:


 * Eigen (C++ library), computer programming library for matrix and linear algebra operations
 * Eigen, Schwyz, settlement in the municipality of Alpthal in the canton of Schwyz, Switzerland
 * Eigen, Thurgau, locality in the municipality of Lengwil in the canton of Thurgau, Switzerland
 * Manfred Eigen (1927–2019), German biophysicist
 * Saint Eigen, female Christian saint
 * Eigen Hayashi (林 英源), Japanese sport shooter