Social innovation is a significant change that occurs in a society. This change is normally done via the creation of a new venture to solve social problems, i.e., social entrepreneurship. However, less is known about social innovations promoted within an existing organisational setting, i.e., social intrapreneurship especially within a developing country. The paper analyses the case of a social intrapreneur who developed an innovative idea during the 2014 Ebola crisis in Sierra Leone. Through the insights obtained, we were able to develop and elaborate on a five-staged model for social innovation and focused on two relevant aspects in social intrapreneurship: internal governance process and external legitimisation and support.