Sustainable luxury is a strategic issue for managers and for society, yet it remains poorly understood. This research seeks to clarify how corporate social responsibility (CSR) actions directly and indirectly (through brand value dimensions) affect consumers’ willingness to pay a premium price (WTPP) for luxury brand products, as well as how a long-term orientation (LTO) might moderate these relationships. A scenario study presents fictional CSR actions of two brands, representing different luxury products, to 1,049 respondents from two countries (France and Tunisia). The results of a structural equation modeling approach show that the luxury brands’ CSR actions negatively affect customer WTPP overall and for each brand. The luxury brands’ functional and symbolic value dimensions positively mediate the effects of CSR actions on WTPP, whereas social value does not. The effects of CSR actions and brand symbolic value on WTTP do not differ between countries. The effect of functional value on WTPP differs across countries, such that it is stronger for high-LTO than low-LTO cultures. Inversely, the effect of social on customer WTPP is stronger for low-LTO than high-LTO cultures. These findings have theoretical and practical implications for luxury brand managers.