The impact of work–family conflict on well-being outcomes is well established, as is the role of social support in buffering perceptions of conflict. What is less well understood is how these relationships vary for different groups of respondents. Using a two-wave longitudinal design with a 12-month time lag and samples of employees (total N = 2183) from Australia, New Zealand, China and Hong Kong, the present research investigated whether the mediating relationships between social support, work–family conflict and well-being outcomes were moderated by gender, geographical region and the presence of dependants in the household. Supervisor support and family support were associated with lower work–family conflict, and hence reduced psychological strain and increased job and family satisfaction, for women and for employees in China and Hong Kong, but not for employees in Australia and New Zealand. However, the presence of dependants was not a significant moderator. Our findings illustrate the importance of exploring gender and national differences in work–family conflict research, particularly the investigation of cross-domain effects.