An emerging view from a broad array of fields is that there should be greater use of evaluations of public policies in general, and the use of randomised controlled trials (RCTs), where feasible, in particular to test the effectiveness of new policies for which there is limited or no evidence about their likely impact. This is because of the potential for RCTs to provide reliable estimates of the causal impacts of the policy being trialled and considered for wider application. There is less evidence, however, on the level of support for such trials as a tool for policy among the general population. In this paper, we provide a summary of an online survey experiment that tested the level of support, and factors associated with support, for policy trials, and RCTs in particular. We found that about half the population supported a trial for a (hypothetical) policy intervention as opposed to introducing the policy to everyone at once. However, only around one-fifth of the population supported implementation of that trial through random assignment. We also found that (randomly assigned) policy area, support from experts for the policy, and party background of the policy instigator had large and significant associations with the level of public support for trials. We conclude that experts and policy makers who support trials in general and RCTs in particular need to engage with the community to explain the benefits, and to learn from community concerns.