Oper may refer to:
- Technology
- Operator
- IRC operator
- Outstanding Physical Education Preparation, a website for PE preparation
- Opera
- Deutsche Oper Berlin, Oper Leipzig, Komische Oper Berlin, Alte Oper
- Romantische Oper, genre of German opera
- Surname
- Andres Oper, Estonian football player
- Mathematics
- Oper (mathematics), a mathematical bundle on a punctured disc, equipped with a flat connection and an additional extra structure (called the oper structure)