BackgroundThe COVID-19 pandemic has hit almost all countries around the globe, seriously affecting the welfare of populations. Spain is especially hard-hit. In this context, the purpose of the present study is to analyze social, demographic, and economic correlates of mental health during the COVID-19 pandemic in the population residing in Spain.MethodThe sample of this cross-sectional study was comprised of 801 participants aged 18 or older and residing in Spain. Data collection was carried out during March and April 2020. Data of mental health (GHQ12) and well-being (Positive and Negative Affect Schedule) indicators, and those of a wide number of social, demographic, and economic variables were recorded. Linear regression models were built to value associations between mental health and social, demographic, and economic indicators.ResultsMental health morbidity was higher in women, younger people, individuals with medium studies, people with fewer children, singles, students, and unemployed individuals. Positive affect was higher among women, people with a high level of studies, those not co-living with dependent seniors, the self-employed, the employed, and those working outside home. Negative affect was negatively associated with age and number of children and was higher among women, people with basic studies, singles, individuals co-living with dependent seniors, homemakers, and students.ConclusionThe most vulnerable populations were found to be women, younger people, people with basic or medium studies, students and individuals with no remunerated activities, single populations, and those co-living with dependent seniors as well as those with a reduced number of children.