Treaty of Washington

The Treaty of Washington may refer to:
 * Treaty of Washington (1805), between the U.S. and the Creek National Council (Muscogee (Creek))
 * Treaty of Washington (1824), two Indian nation treaties, between the U.S. and the Sac (Sauk) and Meskwaki (Fox) (7 Stat. 229), and the Iowa (7 Stat. 231)
 * Treaty of Washington (1826), between the U.S. and the Creek National Council led by Opothleyahola
 * Treaty of Washington, with Menominee (1831), between the U.S. and the Menominee Indian tribe
 * Treaty of Washington (1836), a U.S.–Native American (Ottawa and Chippewa) treaty
 * Webster–Ashburton Treaty of 1842. It settled the border dispute between Canada and the Eastern States, such as Maine and Vermont. It helped to end the slave trade
 * The Oregon Treaty of 1846, which established the US–British frontier west of the Rocky Mountains (today's US–Canada boundary)
 * Treaty of Washington (1855), between the U.S. and Ojibwa
 * The Treaty of Washington (1871), a general agreement between the United States and the British Empire
 * The International Meridian Conference of 1884 in Washington DC, establishing the Greenwich Meridian, the world time zone system and the universal day as international standards
 * The Treaty of Washington (1900) between Spain and the United States
 * The Washington Naval Treaty of 1922 that limited naval armaments
 * The North Atlantic Treaty of 1949 that created NATO
 * The Treaty of Washington (1989), Treaty on Intellectual Property in respect of integrated circuits
 * The Convention on International Trade in Endangered Species of Wild Fauna and Flora, better known as CITES