Knight's (1921) distinction between certainty, risk, and uncertainty could be regarded as the best-known and most frequently used typology of uncertainty in risk management. In his definition of risk, he coined the terms measurable uncertainty (quantitative) and unmeasurable uncertainty (non-quantitative), when only partial knowledge of outcomes such as beliefs and opinions is available. The measurable, quantifiable perspective portrays a type of “basic uncertainty” that can be managed using objective measures, whereas “Knightian uncertainty” refers to immeasurable risks that cannot be calculated. We adopt this intuition as our starting point in developing a framework for uncertainty in supply chain risk management.