Internal branding refers to an organization’s attempts to persuade its staff to buy-in to the organization’s brand value and transform it into a reality. Drawing from self-determination theory and leadership theory, we seek to develop a deeper understanding of the process of internal branding in the nonprofit sector. More specifically, we propose and examine the mediating effects of the staff’s emotional brand attachment, staff service involvement, and the moderating effect of charismatic leadership on the brand orientation behavior–organizational performance relationship using data obtained from the representatives of 301 nonprofit organizations in the United Kingdom. On a general level, the findings suggest that staff emotional brand attachment and staff service involvement are linked to brand orientation and organizational performance. Moreover, charismatic leadership increases the strength of this linkage. All of these findings extend the literature on internal branding.