Background. The COVID-19 pandemic is not only a world health crisis, but also an ordeal for people’s mental health and psychological well-being. The period of the COVID-19 lockdown has changed everyday life and increased anxiety, fears, and stress from habitual activities such as meetings, shopping, and the use of public transport. As the worry and nervousness increase, they threaten the cognitive (Life-satisfaction) and emotional (Happiness) components of well-being. Emotional regulation strategies are a mechanism to cope with the threat. Objective. This study assessed the impact of anxiety, perceived stress from COVID-19, and emotional regulation strategies on well-being during the first weeks of the lockdown in Russia. Design. Questionnaire-based surveys were conducted online from March 31 to April 30, 2020. A total of 589 participants (18 to 73 years of age) were recruited. The Subjective Happiness Scale, Satisfaction with Life Scale, Zung’s Self-Rating Anxiety Scale, Emotion Regulation Questionnaire, and Perceived Source of Stress from COVID-19 scales were used. Results. Among the various sources of stress, only that from restrictions on everyday life impacted well-being. High anxiety, but not perceived stress, decreased the feelings of Happiness and Life-satisfaction. Additionally, emotional regulation strategies played different roles in their impact on well-being: Cognitive reappraisal lowered negative emotions, but emotional suppression increased dissatisfaction with life. Conclusion. These findings suggest that people’s effective and relevant regulation of their emotions during public health emergencies and ability to avoid losses caused by crisis events, have become urgent needs, requiring the development of psychological interventions to support well-being.