The International Peace Bureau (IPB) (French: Bureau International de la Paix), founded in 1891, is one of the world's oldest international peace federations.
IPB was founded under the name Permanent International Peace Bureau (Bureau International Permanent de la Paix). From 1912 onward it used the name International Peace Bureau. Between 1946 and 1961, it was known under the name International Liaison Committee of Organizations for Peace – ILCOP (Comité de liaison international des organisations de paix – CLIOP).
The organisation was awarded the Nobel Peace Prize in 1910 "[For acting] as a link between the peace societies of the various countries". In 1913 Henri La Fontaine was also awarded the Prize "[For his work as] head of the International Peace Bureau". As of 2012, eleven other Nobel Peace Prize laureates have been members of the IPB.
Established in 1992, the Seán MacBride Peace Prize is awarded by the International Peace Bureau to a person or organisation that has done outstanding work for peace, disarmament and/or human rights. It is named after Seán MacBride, chairman of the IPB from 1968–74 and president from 1974-1985.