Psoriasis alters patients’ quality of life. Among the disorders associated with psoriasis, sleep disorders are common, although they are not directly assessed by most quality-of-life scores. Thus, their specific evaluation with dedicated scores is necessary, especially because such disorders alter physical and psychological health. The relationship between psoriasis and sleep disorders has not yet been fully elucidated, but numerous studies in the literature show links between the two. Our study aims to update knowledge about sleep disorders in patients with psoriasis through a review of the scientific literature since 1980. This work covers several topics of interest, such as sleep assessment methods, the prevalence of sleep disorders in patients with psoriasis, factors predictive of sleep disorders in patients with psoriasis, the impact of sleep disorders on comorbidities and quality of life, pathogenic mechanisms, obstructive sleep apnoea and restless leg syndromes, and the impact of biotherapy treatments on sleep disorders in patients with psoriasis.