Background: Vaccination against Ebolavirus is an emerging public health tool during Ebola Virus Disease outbreaks. We examined demand issues related to deployment of Ebolavirus vaccine during the 2014–2015 outbreak in Sierra Leone. Methods: A cluster survey was administered to a population-based sample in December 2014 (N = 3540), before any Ebola vaccine was available to the general public in Sierra Leone. Ebola vaccine demand was captured in this survey by three Likert-scale items that were used to develop a composite score and dichotomized into a binary outcome to define high demand. A multilevel logistic regression model was fitted to assess the associations between perceptions of who should be first to receive an Ebola vaccine and the expression of high demand for an Ebola vaccine. Results: The largest proportion of respondents reported that health workers (35.1%) or their own families (29.5%) should receive the vaccine first if it became available, rather than politicians (13.8%), vaccination teams (9.8%), or people in high risk areas (8.2%). High demand for an Ebola vaccine was expressed by 74.2% of respondents nationally. The odds of expressing high demand were 13 times greater among those who said they or their families should be the first to take the vaccine compared to those who said politicians should be the first recipients (adjusted odds ratio [aOR] 13.0 [95% confidence interval [CI] 7.8–21.6]). The ultra-brief measure of the Ebola vaccine demand demonstrated acceptable scale reliability (Cronbach's α = 0.79) and construct validity (single-factor loadings > 0.50). Conclusion: Perceptions of who should be the first to get the vaccine was associated with high demand for Ebola vaccine around the peak of the outbreak in Sierra Leone. Using an ultra-brief measure of Ebola vaccine demand is a feasible solution in outbreak settings and can help inform development of future rapid assessment tools.