DSN may refer to:
- Data set (IBM mainframe) Name, the name of a computer file having a record organization
- Data Source Name, a data structure used to describe a connection to a data source
- Deep Space Network, a communication network that supports interplanetary spacecraft missions
- Star Trek: Deep Space Nine, a science fiction television program that originally aired from 1993 to 1999
- Defense Switched Network, a communications network operated by the United States Department of Defense
- Delivery Status Notification message, an automated electronic mail message about a delivery problem
- Distributed social network, a social network that is decentralised and distributed across multiple providers.
- International Conference on Dependable Systems and Networks, an annual conference on dependable computer systems and reliable networks
- DSN DASH, the U.S. Navy's Drone Anti-Submarine Helicopter.