The study aimed to examine what types of social support a prominent online peer support group has provided to Filipino domestic workers (FDWs) in Hong Kong (HK), how impactful each type of support was, and to what extent the support could address group members’ expressed needs. Posts published from 1 September 2021 to 31 December 2021 in one of the largest online peer-support groups for FDWs in HK and their meta-data were extracted from Facebook. Thematic content analysis was performed to extract relevant information from the posts. Descriptive statistical analysis on the social media metrics was conducted to measure post impacts. A total of 599 posts published over the study period can be categorized to provide informational (76.67%), emotional (33.56%), and instrumental support (13.52%). Posts including emotional support were often more impactful. A total of 58 posts responded to requests explicitly expressed by individual FDWs, of which 13 required external resources. The online peer-support group acts as a new channel to raise FDWs’ awareness of important issues related to their well-being, to encourage and facilitate them to seek formal and informal help, and to keep them emotionally attended to. Formal support services should recognize and collaborate with them and support their long-term sustainability.