DDA may refer to: Dda (DNA-dependent ATPase), a DNA helicase Delhi Development Authority, the planning agency for Delhi, India Demand deposit account, a deposit account held at a bank or other financial institution Demand-driven acquisition, a model of library collection development Digital differential analyzer, a digital implementation of a differential analyzer Digital differential analyzer (graphics algorithm), a method of drawing lines on a computer screen Disability Discrimination Act 1992, Australian legislation Disability Discrimination Act 1995, UK legislation Discontinuous Deformation Analysis, an analysis procedure used in physics and engineering Discrete dipole approximation, method for computing scattering of radiation by particles of arbitrary shape Division on Dynamical Astronomy, a branch of the American Astronomical Society Doha Development Agenda of the World Trade Organization Dual Dynamic Acceleration, an Intel technology for increasing single-threaded performance on multi-core processors Dutch Dakota Association, a Dutch organisation dedicated to preserving and operating classic aircraft Dynamic difficulty adjustment or dynamic game difficulty balancing, a method of automatically adjusting video game difficulty based on player ability