Henry Walton Grinnell

Henry Walton Grinnell
Portrait from Grinnell's 1920 obituary in the Boston Daily Globe
Birth nameHenry Walton Grinnell
Nickname"Mikado's Yankee Admiral"
Born(1843-11-19)19 November 1843
Died2 September 1920(1920-09-02) (aged 76)
AllegianceUnited States of America
Empire of Japan
Republic of Ecuador
BranchUnited States Navy
Imperial Japanese Navy
Ecuadorian Navy
Service years1861-1868, 1898-1899 (United States)
1868-1895 (Japan)
1871-1872 (Ecuador)
RankLieutenant (United States)
Vice admiral (Japan)
ConflictsAmerican Civil War
 • Capture of New Orleans
 • Battle of Mobile Bay
 • Carolinas campaign
First Sino-Japanese War
 • Battle of the Yalu River
Spanish–American War
 • USS Iowa
AwardsMentioned in dispatches

Henry Walton Grinnell (November 19, 1843 – September 2, 1920) was an American naval officer who served in the American Civil War and Spanish–American War. He was Inspector General of the Imperial Japanese Navy from 1868 to 1870, retaining the rank of rear admiral through victory in the First Sino-Japanese War. Working in tandem with other foreign experts, Grinnell was credited with modernizing the Japanese navy in the late 19th century.