DDN may refer to:
Arts, media and entertainment Daydream Nation, a music album by Sonic Youth Dayton Daily News, a daily newspaper in Dayton, Ohio, US Digital Delivery Network, a service of the Community Radio Network in Australia Digital Distribution Netherlands, a Dutch digital music distributor Double Down News, an alternative media outlet in the UK Dustin's Daily News, a comedic current affairs TV show
Computing DataDirect Networks, a data storage company Defense Data Network, a separate instantiation of the ARPANET used by the U.S. Department of Defense from 1983 to 1995 Dot-decimal notation, a human readable way to write IPv4 internet addresses
Other uses Dehradun railway station (station code), India Digital Divide Network, an online community of activists