Adonijah is the fourth son of King David in the Bible. The given name may also refer to:
Biblical figures A Levite sent with the princes to teach the book of the law to the inhabitants of Judah () One of the "chiefs of the people" after the Babylonian captivity ()
People Adonijah Bidwell (1716–1784), colonial American minister and supporter of American independence Adonijah Reid (born 1999), Canadian soccer player Adonijah Welch (1821–1889), United States Senator from Florida and the first president of Iowa State Agricultural College
See also Jacob ben Hayyim ibn Adonijah (c. 1470–before 1538), Jewish biblical scholar