The ambassador of the United States of America to Japan (Japanese: 日本駐在米合衆国大使, Hepburn: Nihon Chūzai Amerika Gasshūkoku Taishi) is the ambassador from the United States of America to Japan.

Beginning in 1854 with the use of gunboat diplomacy by Commodore Matthew C. Perry, the U.S. has maintained diplomatic relations with Japan, except for the ten-year period between the attack on Pearl Harbor in 1941 (and the subsequent declaration of war on Japan by the United States) and the signing of the Treaty of San Francisco, which normalized relations between the United States and Japan.

The United States maintains an embassy in Tokyo, with consulates-general in Osaka, Nagoya, Sapporo, Fukuoka, and Naha.

Due to the significance of the relations between the two countries in recent years on trade and defense, with Japan being described by the United States State Department as "the cornerstone of the U.S. security interests in Asia," [1] the post has been held by many significant American politicians, including Mike Mansfield, Walter Mondale, Tom Foley and Howard Baker and Rahm Emanuel.

Resident ministers Envoys extraordinary and ministers plenipotentiary Ambassadors extraordinary and plenipotentiary