Der or DER may refer to:

Places

* Darkənd, Azerbaijan * Dearborn (Amtrak station) (station code), in Michigan, US * Der (Sumer), an ancient city located in modern-day Iraq * d'Entrecasteaux Ridge, an oceanic ridge in the south-west Pacific Ocean

Science and technology

* Derivative chromosome, a structurally rearranged chromosome * Distinguished Encoding Rules, a method for encoding a data object, including public key infrastructure certificates and keys * Distributed Energy Resources * ∂, the partial derivative symbol * Derivation (differential algebra) on an algebra ''A'' over a field ''K'', the space (module) of which is denoted Der_''K''(A) * Deep energy retrofit, an energy conservation measure

Organizations

* Digital Education Revolution, former Australian Government-funded educational reform program * DER rental (Domestic Electric Rentals Ltd), a UK television rentals company * Documentary Educational Resources, a non-profit film producer and distributor

Other uses

* Defence (Emergency) Regulations, legal regulations promulgated by the British in Mandatory Palestine in 1945 * Department of Environment Regulation, former Western Australian state government department * Federal Aviation Administration#Designated Engineering Representative, Designated Engineering Representative, an individual appointed to approve, or recommend approval, of technical data to the Federal Aviation Administration {{disambiguation, geo