DEQ
- Arkansas Department of Environmental Quality
- DEK (disambiguation)
- Dec (disambiguation)
- Delivered Ex Quay
- Deq (tattoo)
- Deqing Moganshan Airport
- Double-ended queue
- Drug Effects Questionnaire
- Equatorial diameter
- Idaho Department of Environmental Quality
- J. Lynn Helms Sevier County Airport
- Louisiana Department of Environmental Quality
- Michigan Department of Environmental Quality
- Montana Department of Environmental Quality
- Oklahoma Department of Environmental Quality
- Oregon Department of Environmental Quality
- Utah Department of Environmental Quality