Hornblower is a surname. Notable people with the surname include:
Jabez Carter Hornblower (1744–1814), pioneer steam engineer
Joseph Hornblower (1696?–1762), steam pioneer who installed Newcomen engines in Cornwall
Joseph Coerten Hornblower (1777–1864), American lawyer and Chief Justice of the New Jersey Supreme Court
Josiah Hornblower (1729-1809), steam pioneer and American politician
Jonathan Hornblower (1753-1815), Cornish engineer and inventor
Jonathan Hornblower (1717) (1717-1780), steam pioneer, father of Jonathan and Jabez Hornblower
Ralph Hornblower III (born 1948), American lawyer and operatic tenor
Simon Hornblower (born 1949), Professor of Classics at University College London
William B. Hornblower (1851-1914), New York jurist
Nathanial Hörnblowér, a pseudonym of the musician MCA