- David Elkind
- David Hume
- David Shakow
- David Wechsler
- Daydreaming
- Deductive Reasoning
- Defense Mechanisms
- Delay of Gratification
- Delayed Response
- Delirium
- Delusion/Delusional Disorders
- Dementia
- Dendrite
- Deoxyribonucleic Acid (DNA)
- Dependent Personality Disorder
- Dependent Variable
- Depression
- Depth Perception
- Desensitization
- Determinism
- Developmental Delay
- Developmental Psychology
- Developmental Reading Disorder
- Developmental Stages, Theories of
- Diagnostic and Statistical Manual of Mental Disorders (DSM-IV)
- Differential Psychology
- Disability
- Dissociation/Dissociative Disorders
- Dissociative Identity Disorder
- Divergent Thinking
