John Howell may refer to:

• John Howell (athlete) (born 1936), British Olympic long jumper
• John Howell (bobsleigh) (1955–2006), British Olympic bobsledder
• John Howell (cricketer) (1943–2010), New Zealand cricketer
• John Howell (defensive back) (born 1978), National Football League safety
• John Howell (halfback) (1915–1946), National Football League halfback

• John Howell (art director) (1914–1993), British film set designer
• John Howell (activist) (1933–1988), community activist in Atlanta, Georgia
• John Howell (MP for Exeter), 17th century, English MP for Exeter, 1601
• John Howell (politician) (born 1955), British Member of Parliament
• John Howell (polyartist) (1788–1863), Scottish inventor in Edinburgh
• John Howell (pioneer) (1809–1874), New Zealand whaler, trader, pastoralist, and politician
• John Adams Howell (1840–1918), rear admiral of the United States Navy, served in the American Civil War and the Spanish–American War; also a noted inventor.
• John Cummings Howell (1819–1892), rear admiral of the United States Navy, served in the American Civil War
• John McDade Howell (1922–2016), American academic; chancellor of East Carolina University
• John Bruce Howell (1941–1997), American librarian and bibliographer
• John H. Howell, US Army artillery officer
• John Henry Howell (1869–1944), New Zealand technical college principal and Quaker
• John Morgan Howell (1855–1928), political figure in Cardiganshire, Wales
• John Thomas Howell (1903–1994), American botanist and taxonomist
• John White Howell (1857–1937), American electrical engineer

• John Howell & Son, 19th-century British engineering company

• Jack Howell (disambiguation)
• John Mead Howells (1868–1959), American architect