LDR may refer to:
- European Liberal Democrat and Reform Party (European Parliament group), abbreviated as LDR from 1985 to 1994
- Labor and delivery room, rooms in hospitals used for childbirth
- Lana Del Rey, an American singer-songwriter
- Lateral digit reduction, a concept in paleontology to explain the wing formation in birds; see Origin of birds#Digit homology
- Laval-des-Rapides, a borough in Laval, Quebec, Canada
- .ldr, the file extension for LDraw 3D modeling software
- Lecture and dissertation room, a large room used for instruction, typically at a college or university
- Light dependent resistor or photoresistor, an electronic component
- Lift-to-drag ratio, in aerodynamics
- Long-distance relationship, an intimate relationship that takes place when the partners are separated by a considerable distance
- Low dynamic range rendering, a term used in 3D computer graphics rendering; compare with high dynamic range rendering