Seaver is a surname, and may refer to:

• Benjamin Seaver (1795–1856), American politician from Massachusetts; mayor of Boston 1852–53
• Blanche Seaver (1891–1994), American philanthropist and musician
• Ebenezer Seaver (1763–1844), American politician from Massachusetts; U.S. representative 1803–1
• Edwin Seaver (1900–1987), American publisher, writer, editor, critic
• Frank Seaver (1883–1964), American lawyer, Navy officer, oil executive, philanthropist
• Fred Jay Seaver (1877–1970), American mycologist
• Jay Webber Seaver (1855–1915), American physician and pioneer of anthropometry
• Kirsten Seaver (1934-) Norwegian-American historian
• Kristjan Seaver (1898–1941), Estonian Communist politician
• Michael Seaver (born 1967), Irish musician and dance critic
• Robert Chauncey Seaver (fl. 1907), American amateur tennis player
• Thomas O. Seaver (1833–1912), American army officer during the American Civil War; recipient of the Medal of Honor
• Tom Seaver (1944–2020), American baseball pitcher

• Siever, surname