Nudge is an approach to public policy that changes the decision-making environment to encourage citizens to make a particular choice. The approach has been eagerly adopted by administrations around the world, with some governments establishing dedicated nudge units to advance their use. One reason proposed for nudge's popularity is that it supports evidence-based policy. Nudging seems to be firmly positioned in evidence-based policy rhetoric, and encourages the use of Randomised Control Trials to determine the effectiveness of a policy. There is little empirical understanding on whether nudge's association with this rhetoric has contributed to its increasingly widespread application. This research explores how nudge is understood in relation to the evidence-based movement, from the perspective of those designing, developing and implementing nudge policies. In-depth, qualitative interviews were undertaken with policymakers in Australia. This paper finds policymakers perceive an interconnected relationship between nudging and evidence-based policy, with each providing fertile ground for the growth of the other. Consequences for scholarship and practice are discussed including implications for what constitutes legitimate evidence in the public service.