The medal will be presented to Blair in Philadelphia on Sept. 13 by former President Bill Clinton.
The ceremony will be broadcast live on 6abc and webcast live on 6abc.com. Jim Gardner will serve as the host.
RELATED LINK: The National Constitution Center.
The National Constitution Center gives the annual award to individuals or organizations whose actions strive to bring liberty to people around the world.
The medal was first awarded in 1989. Previous winners have included rock singer and human rights activist Bono, former South African President Nelson Mandela and former U.S. President Jimmy Carter.
The National Constitution Center says Blair played a critical role in advancing peace in Northern Ireland during his tenure as British prime minister. Throughout the grueling negotiation process that preceded the historic Good Friday Accord, he displayed unwavering determination to settle the generations-long conflict.
Since leaving government, former Prime Minister Blair has continued to facilitate productive dialogue between diverse groups, as Quartet Representative to the Middle East for the United Nations and through the Tony Blair Faith Foundation.
The Associated Press contributed to this report.