John Ash

John Ash may refer to:
 * John Ash (physician) (1723–1798), British physician
 * John Ash (divine) (c. 1724–1779), lexicographer and minister
 * John Ash (Canadian politician) (1821–1886), Member of the Legislative Assembly for Comox riding in British Columbia, Canada
 * John Ash (ornithologist) (1925–2014), British ornithologist
 * John Ash (writer) (1948–2019), poet, writer and travel writer
 * John Ash (MP for Totnes) (fl. 1420–1439), English politician