A deliberative referendum is a referendum that increases public deliberation through purposeful institutional design.^[1] The term "deliberative referendum" stems from deliberative democracy,^[2] which emphasises that "the legitimacy of decisions can be increased if...decisions are preceded by authentic deliberation."^[3] Deliberative design features can promote public deliberation prior to and during the referendum vote to increase its actual and perceived legitimacy.^[4] Deliberative referendums encourage open-minded and informed reasoning, rather than rigid "pre-formed opinions".^[5] "[A]fter deliberations, citizens routinely alter their preferences".^[4]

In practice, a deliberative referendum includes a variety of institutional design features. These include using a citizens' jury to set referendum questions and educate the public, further public education via mandatory interactive tutorials before voting, and focusing referendums on broad values rather than technicalities.^[6] Some authors note how legal regulation can also aid referendum deliberation.^[7]

One deliberative referendum method increasingly in use is the Citizens' Initiative Review; this is a randomly-selected body, similar to a citizen's jury, convened specifically to deliberate on a ballot initiative or referendum that voters in the same jurisdiction (such as a city, state, province, or country) will later vote on.^[8]

Constitutional deliberative referendums can "provide citizens with a meaningful say in determining the most fundamental constitutional decisions that affect their lives".^[9] Voter deliberation is significant here as the referendum result could change the state's political status or impact the enjoyment of human rights.^[10]