Planning for energy futures is essentially a multi-criteria problem in which decision makers must evaluate competing energy supply alternatives, and often conflicting objectives, in order to select a preferred, practicable energy future. Up until the 1960s, decision methods to support planning for energy futures were dominated by simple optimization methods, including cost benefit analysis, which assigns monetary values to objectives and criteria and discounts cost and benefit streams for alternatives to a single ‘net present value’ (Voogd 1983); public choice theory, which examines ways of incorporating individual views and opinions into a consultation that seeks to maximize collective satisfaction (Massam 1988); and multi-attribute utility theory, which seeks to identify the individual utility function of a single decision maker (Voogd 1983). The majority of these methods however address only single-objective problems and, as a result, a systematic analysis of conflicts and competing attributes involved in energy futures planning often received insufficient attention. One of the main deficiencies in energy resource and supply decision making was the absence of an analytical framework that integrated and incorporated competing information, multiple decision criteria, and the values of multiple decision makers. Such a framework would allow a more systematic and comprehensive examination of the overall implications of energy supply choice possibilities. Accordingly, this chapter discusses the role of multi-criteria decision making (MCDM) in the energy resource sector – specifically with regard to the assessment of alternative electrical generation and supply options (Noble 2004). The primary focus is on the contribution MCDM can make to energy resource planning. The nature of multi-criteria decision support in planning energy futures is discussed, and a MCDM application within the context of the Canadian energy resource sector presented.