AbstractSelf‐affirmations—responding to self‐threatening information by reflecting on positive values or strengths—help to realign working self‐concept and may support adaptive coping and wellbeing. Little research has been undertaken on spontaneous self‐affirmations in response to everyday threats, and less has been undertaken on the relationships between spontaneous self‐affirmations, coping, and wellbeing. This study aimed to test both within‐ and between‐person relationships between spontaneous self‐affirmations, coping, and wellbeing, controlling for threat intensity and other outcomes. A repeated survey assessment design was adopted to achieve these aims. Outcome measures included approach coping, avoidance coping, positive affect, negative affect, and eudaimonic wellbeing. It was found that spontaneous self‐affirmations positively predicted approach coping and positive affect at both within‐ and between‐person levels, and eudaimonic wellbeing at the between‐person level. Overall, spontaneous self‐affirmations were positively associated with approach coping and aspects of wellbeing.