Background and objectives <p>A&#xa0;non-negligable portion of COVID survivors presents with symptoms longer than the acute infection. In many cases, this includes sleep disorders. We focus on the relevance of sleep within post-COVID disorder, its mechanisms and its risk factors.</p> Materials and methods <p>A&#xa0;systematic literature search was performed. Before evaluation, relevant literature was categorised into epidemiology, associations, timeline, therapy and mechanisms.</p> Results <p>Epidemiological data is broadly available. The specific populations studied vary greatly in their composition. Sleep disorders are a&#xa0;relevant part of post-COVID symptoms. The risk seems to be higher in women and patients who survived a&#xa0;severe acute COVID disease and reduced in patients with a&#xa0;high quality of sleep. Similar secondary syndromes are also described in other infectious diseases. Symptoms seem to follow an exponential decrease pattern with sleep symptoms persisting for at least five years. The literature lacks relevant research focusing on therapy. Multiple mechanistic models are described, including somatic approaches like organ damage or persisting inflammation as well as psychological approaches.</p> Conclusions <p>The results suggest a bidirectional relationship between post-COVID and sleep: on the one hand, sleep disorders are an important part of post-COVID; on the other hand, sleep quality seems to lower the risk of developing post-COVID symptoms.</p> <p>There is still potential for research unifying different mechanisms and methods like points of evaluation in time.</p>