For the mathematical operation of adding, see
Addition.
ADD is a three-letter acronym that may refer to:
- Adela, Dumitrita, Diana - Co-founders of PRADD SRL.
- Attention deficit disorder, a condition now known as attention-deficit hyperactivity disorder - predominantly inattentive, or ADHD-PI.
- People diagnosed with Attention deficit disorder.
- National rail code for Adderley Park railway station, United Kingdom.
- Administration on Developmental Disabilities, of the United States Administration for Children and Families.
- Advanced Dungeons & Dragons
- Ang Dating Daan, a radio-television program in the Philippines
- An assembly language computer instruction to add two numbers
- Bole International Airport, Addis Ababa, Ethiopia, from its IATA airport code
- Arab Digital Distribution, a pay television network in the Middle East and North Africa
- Architectural Design Document, describes the architectural design using the software requirements and the logical model (defined in the Software Requirements Document - SRD)
- A SPARS code appearing on some compact disc recordings, telling the consumer that the recording was made on analog (A) equipment and digital (D) equipment was used to mix/edit and master the recording
- ADD2 (Advanced Digital Display 2), a designation for Intel SDVO adapter cards
- Accumulated degree days, calculated by summing average daily temperatures and used to determine the state of temperature dependent processes, usually biological
- ADD model, a hypothesis in physics to explain the weakness of gravity relative to the other forces
- ADD, a slang acronym for Asian Drinking Disorder, referring to the Alcohol flush reaction
- "A.D.D. (American Dream Denial)", a song on System of a Down's album Steal This Album!
- A.D.D. (Audio Day Dream), the first studio album by Blake Lewis, the runner-up on the sixth season of American Idol
