is the name of:
- Alonzo C. Babers (b. 1961), a U.S. athlete.
- Alonzo Bodden, a U.S. comedian.
- Alonzo Church (1903–1995), a U.S. mathematician.
- Alonzo Clemons, a U.S. autistic savant clay sculptor.
- Alonzo Barton Cornell (1832–1904), a Governor of New York.
- Alonzo Jay Edgerton (1827–1896), a U.S. politician.
- Alonzo Dillard Folger (1888 –1941), a U.S. politician.
- Alonzo Arza Hinckley (1870–1936), a U.S. official of the Church of Jesus Christ of Latter-day Saints.
- Alonzo Horton (1813–1910), developer of San Diego, California.
- Alonzo Clark Mather (1848–1941), founder of the Mather Stock Car Company.
- Alonzo Mourning (b. 1970), a U.S. basketball player.
- Martin Alonzo Pinzón(c. 1441–1493), a Spanish navigator.
- Alonzo Sargent, (fl. 1918) a U.S. locomotive engineer.
- Amos Alonzo Stagg (1862–1965), U.S. sports coach.
The following fictional characters have the name Alonzo: