Background: Despite benefits, many mothers stop breastfeeding soon after birth. A common reason for this is the experience of pain or discomfort. One resource which women use to share their breastfeeding challenges and seek support are online forums. This study aimed to collect data from online forums to explore 1) usage of forums as social support for breastfeeding related pain; 2) experiences of breastfeeding related pain; 3) perceptions and strategies to deal with breastfeeding related pain; and 4) the impact of pain on breastfeeding duration. Methods : This secondary analysis of data involved searches of online forums: Netmums, What to Expect and Mumsnet using key terms including ‘ painful breastfeeding’ and ‘sore breastfeeding’ . Data included 123 posts and 193 replies, which were analysed using thematic analysis. Results: The first theme identified was ‘variation in types of pain’, highlighting the variety of painful experiences and their descriptions. Secondly, ‘perceived causes and explanations for pain’ revealed pain ascribed being due to a recognised condition or behavioural cause. The third theme ‘cessation of breastfeeding related to pain’ identified both physical and psychological struggles related to breastfeeding and cessation. Finally, ‘shared experiences and support’ identified practical or emotional support to deal with pain. Conclusion: Pain was a key reason for breastfeeding cessation, commonly associated with strong feelings of guilt. The online forums provide a unique form of social support for breastfeeding women to find ways to cope with the pain, while highlighting the urgent need for more appropriate antenatal education on realistic expectation surrounding breastfeeding.