Background: A range of studies found that spending time outdoors in daylight provided substantial benefits for the psychosocial well-being of older people. Good psychosocial well-being is essential in maintaining overall health as people age and often contributes to adequate physical functioning. Objectives: The overall objective of this study was to undertake a systematic review on the effects of spending time outdoors in daylight on the psychosocial well-being of older people and their family carers. Inclusion criteria Types of participants This review considered studies that included older people aged 55 years or more, including those living in a community or residential accommodation setting. In addition, this review considered family carers, who were defined as unpaid relatives or friends of an older person, who helped that individual with their activities of daily living. Types of intervention(s): The intervention of interest was spending time outdoors in daylight. Types of studies All experimental and epidemiological study designs including randomized controlled trials and non-randomized controlled trials published in the English language were included in this review. Types of outcomes: This review considered studies that included objective and/or subjective measures of psychosocial well-being for older people and their family carers. Search strategy The search aimed to find published and unpublished studies through electronic databases, reference lists, key reports and the World Wide Web. An extensive search was undertaken for the following databases: MEDLINE, CINAHL, Wiley Online Library, ProQuest Central, Scopus, and the Cochrane Library. Databases were searched up to December 2013. Methodological quality: Methodological quality was assessed independently by three reviewers using the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) checklists. Disagreements that arose between the reviewers were resolved through discussion. Data collection: Quantitative data were extracted from papers included in the review using the standardized data extraction tool from JBI-MAStARI. The data was individually extracted by two reviewers. Disagreements that arose between the reviewers were resolved through discussion. All results were subject to double data entry. Data synthesis: For this review statistical pooling of the data was not possible due to the heterogeneity of the studies; therefore, the findings are presented in narrative form. Results: A total of 13 studies were included in the final review. In the four studies that evaluated the effects of exposure to daylight on behavioral disturbances, there was no evidence of effect of daylight hours on physical and verbal aggression. There was some evidence to indicate that exposure to daylight for a period of time resulted in fewer depressive symptoms. Increasing the frequency of going outdoors was associated with better cognitive preservation over a one year period. Similarly exposure to daylight resulted in improved social functioning and improved quality of life. There were no studies that evaluated the effect of spending time outdoors in daylight on the psychosocial well-being of family carers, including carer satisfaction or carer stress.