XDR is a three-letter acronym with multiple meanings:
- XDomainRequest, AJAX-Technology
- External Data Representation, an implementation of the OSI model presentation layer
- XDR DRAM, or extreme data rate dynamic random-access memory
- XDR (audio) or eXtended Dynamic Range, a quality-control system for pre-recorded audio cassettes
- Extensively drug-resistant, for example:
- Extensively drug-resistant tuberculosis (XDR-TB)
- XDR Schema
- External Data Representation (RFC-1014)
XDR may also refer to:
- ISO 4217 currency code of special drawing rights, a monetary unit of the International Monetary Fund
- XDR, a video game for the Sega Mega Drive.