This observational cross-sectional study aims to determine chronic pain phenotypes in individuals with multiple sclerosis (MS) and to investigate the clinical characteristics associated with different pain phenotypes. Participants with MS and chronic pain will undergo a comprehensive clinical assessment to identify nociceptive, neuropathic, nociplastic, and mixed pain phenotypes. The assessment will include clinical history, pain characteristics and distribution, quantitative sensory testing, pain intensity, disease severity, fatigue, health-related quality of life, and pain catastrophizing. The clinical characteristics of participants with different pain phenotypes will subsequently be compared.