Appleby is an Old English surname, and combines Apple or Appel, indicating an apple, and the Danish suffix by meaning 'settlement', indicating someone who lived near an apple orchard, or someone who farmed apples. Notable people with the surname include:
- Anne Appleby (born 1954), American painter
- Austin Appleby (born 1993), American football quarterback
- Ben Appleby (1876–1961), English footballer
- Charlie Appleby (born 1975), British racehorse trainer
- Flynn Appleby (born 1999), Australian rules footballer
- Fred Appleby (1879–1956), English long-distance runner
- Jim Appleby (1934–2014), English footballer
- John Appleby (1840–1917), American inventor
- John Appleby (? - 1975), British novelist
- Kim Appleby (born 1961), British singer
- Louis Appleby, British psychiatrist
- Melanie Appleby (1966–1990), British singer; sister of Kim
- Shiri Appleby (born 1978), American actress
- Stephen Appleby (1912–1984), British pilot
- Steven Appleby (born 1956), cartoonist, illustrator and artist living in Britain
- Stuart Appleby (born 1971), Australian golfer
- Susanna Appleby (1689–1769), English antiquarian
- Ken Appleby (born 1995), Canadian ice hockey player
Fictional characters:
- Appleby (Catch-22), a character in the novel Catch-22
- Sir Humphrey Appleby, a fictional character in the television series Yes, Minister
- Sir John Appleby, a fictional detective created by Michael Innes