Shigeo Yamada (山田 重夫, Yamada Shigeo) is a Japanese diplomat who is serving as Japanese Ambassador to the United States since 2023.

Shigeo Yamada was born in Tokyo on July 7, 1964. While studying law at Keio University he passed the foreign service exam and joined the Ministry of Foreign Affairs in 1986. After graduating in 1987 he was sent to further his education at Carleton College in the United States, where he graduated in 1989.^[1][2]

Yamada's earlier diplomatic career included postings in Washington, London and Beijing. From 2012 to 2015 he served as minister for political affairs at the Embassy of Japan in Washington. After returning to Japan he was seconded to the National Security Secretariat, before being appointed Deputy Minister for Foreign Policy at the Ministry of Foreign Affairs in 2019. He was a confidant of Toshimitsu Motegi who was Foreign Minister from 2019 to 2021.^[1][3]

In 2021 Yamada was appointed Senior Deputy Minister for Foreign Affairs. He played an instrumental role in making Prime Minister Fumio Kishida's surprise visit to Ukraine in March 2023 possible. Yamada was a leading candidate to succeed Administrative Vice Minister Takeo Mori [ja] along with Assistant Chief Cabinet Secretary Masataka Okano [ja]. In the end, the position went to Okano while Yamada became the prospective next ambassador to the United States.^[1][3]

After being formally appointed in October 2023, he took the position in December 2023. He was reportedly instructed to make connections with the campaign of former President Donald Trump in anticipation for his possible victory in the 2024 United States presidential election.^[4][5]

On 10 April 2024, Yamada was among the guests invited to the state dinner hosted by U.S. President Joe Biden in honor of Prime Minister Fumio Kishida at the White House.^[6]