Background and Purpose Depression is common and debilitating illness accompanying many neurological disorders including non-traumatic subarachnoid hemorrhage (SAH). The aim of this systematic review was to identify and critically appraise all published studies that have reported the frequency, severity and time course of depression after SAH, the factors associated with its development and the impact of depression on patients’ quality of life after SAH. Methods The PubMed database was searched for studies published in English that recruited at least 40 patients (>18 years old) after SAH who were also diagnosed with depression. Results Altogether 55 studies covering 6,327 patients met study entry criteria. The frequency of depression ranged from 0% to 61.7%, with a weighted proportion of 28.1%. Depression remained common even several years after the index SAH. Depression after SAH was associated with female sex, premorbid depression, anxiety, substance use disorders or any psychiatric disorders, and coping styles. Comorbid cognitive impairment, fatigue, and physical disability also increased the risk of depression. Aneurysmal SAH and infarction may be related to depression as well. Depression reduces the quality of life and life satisfaction in patients after SAH. Conclusions Depression is common after SAH and seems to persist. Further research is needed to clarify its time course and identify the neuroendocrine and neurochemical factors and brain circuits associated with the development of post-SAH depression. Randomized controlled treatment trials targeting SAH-related depression are warranted.