The Croat federal unit in Bosnia and Herzegovina, or Croat entity, also informally known as the third entity (), is a proposed administrative unit in Bosnia and Herzegovina based on territorial federalism and ethnic self-determination. The proposal has been invoked by several political scientists, politicians and political parties, including the Croat National Assembly (HDZ BiH, HDZ 1990 and HSS). So far it has not been discussed beyond the concept level. Since the country is divided into two entities, the Serb-dominated Republika Srpska and the Bosniak-majority Federation, Croats, as one of the three equal constitutive nations, have proposed creating a symmetrical Croat-majority territorial unit. Political advocates for such proposal argue it would ensure Croat equality and prevent electoral gerrymandering, simplify the political gridlock while dismantle overburdening administration. Opponents argue it would further divide the country on ethnic grounds thus breaching the constitutional principles, put non-Croats in a subordinate position, and lead to separatism.
Background
Bosnian War and Herzeg-Bosnia
During the Bosnian War (1992–95), Bosnian Croats founded their own sub-national entity, Herzeg-Bosnia, which de facto functioned as a mini state, with its own army, police, parliament etc.

Peace plans
During the Bosnian War, international mediators and envoys proposed several peace plans that included forming three federal units in Bosnia and Herzegovina. In 1992, EC diplomat José Cutileiro sketched a proposal in which he stated that the three constituent units would be "based on national principles and taking into account economic, geographic, and other criteria". In late July 1993, representatives of Bosnia-Herzegovina's three warring factions entered into a new round of negotiations. On 20 August, the UN mediators, Thorvald Stoltenberg and David Owen, unveiled a map that would organise Bosnia into three ethnic mini-states. Bosnian Serb forces would be given 52% of Bosnia-Herzegovina's territory, Muslims would be allotted 30 percent and Bosnia Croats would receive 18 percent. Sarajevo and Mostar would be districts belonging to none of the three states. On 29 August 1993 the Bosniak side rejected the plan.

(Con)federal structure
In 1994, under the Washington Agreement, Croats joined their territory, Herzeg-Bosnia, with the Bosniak-government controlled areas (the Republic of Bosnia and Herzegovina) to create a subnational entity, the Federation of Bosnia and Herzegovina (FBiH) with joint institutions. The 1995 Dayton Agreement that ended the war left the country divided into two political entities, the Serb-dominated and controlled Republika Srpska and the Bosniak-Croat Federation. FBiH was further divided into 10 autonomous cantons to ensure equality. The FBiH government and a bicameral Parliament were supposed to guarantee power-sharing and equal representation to the less numerous Croats. Some dissatisfaction with this situation was displayed by Croats already in 1999 together with the calls for an establishment of a Croat-majority federal unit, but the Croat member of the state presidency dismissed it and called for strengthening of the principle of equality of three communities and of canton autonomy.






