Markets for biomass are emerging across Canada; however, considerable concern has been expressed regarding the ability of Canada’s arable land base to sustainably meet this emerging demand. Using Ontario as a case study, economic and environmental factors that must be considered when designing biomass production systems based on either crop residues from maize (Zea mays L.), soybean [Glycine max (L.) Merr.], or winter wheat (Triticum aestivum L.) or on dedicated biomass crops such as Miscanthus (Miscanthus spp.) or switchgrass (Panicum virgatum L.) are reviewed. The Ontario agricultural land base is characterized by a growing prevalence of maize and soybean rotations, a high percentage of total arable land under the Canada Land Inventory categorized as Class 1 and 2, and geographically dispersed Class 3–5 land. Economic and environmental risks and opportunities of biomass production are demonstrated to be a function of the source of biomass, land availability, land classification, and existing land use patterns.