Naturalism might refer to:
- Philosophical naturalism - Disbelief in the supernatural.
- Methodological naturalism - Leaving supernatural claims out of science.
- Movements within literature and theatre that emphasise natural and realistic situations over surreal or supernatural ones. The rise of this is attributed to the advances in naturalistic science in the 19th Century and manifests quite clearly in opera, where prior to the naturalism movement the plots and stories would revolve around gods, myths and legends. Following the naturalism movement, the plots would then began to focus on real people in grittier situations, with a greater focus on character.