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, born 1949), Japanese sport shooter
See also
edit- Eigenvalue, eigenvector and eigenspace in mathematics and physics
- Eigenclass, synonym to metaclass in the Ruby programming language
- Eigenbehaviour, with its connection to eigenform and eigenvalue in cybernetics