The ceremony was held under the auspices of Croatian President Ivo Josipovic and Bosnian Presidency Chairman Nebojsa Radmanovic.
Leko is the first Croat of Bosnian descent who became the speaker of the Croatian parliament, organisers said.
Accepting the award, Leko said Bosnia and Herzegovina and Croatia would remain connected also after Croatia joins the European Union on July 1. "BiH and Croatia aren't only neighbouring countries. They are more than partners. We genuinely and wholeheartedly support a BiH with three equal peoples and represent it and wait for it in the EU family of peoples and states."