Thorndike or Thorndyke may refer to:

People

• Andrew Thorndike (1909–1979), a German film director
• Ashley Horace Thorndike (1871–1933), an American educator
• Augustus Thorndike (1896–1986), an American physician
• Edward Thorndike (1874–1949), a behavioral psychologist
• Elizabeth Thorndike (1632–1672), the second wife of John Proctor, daughter of John Thorndike
• Frances Cope (1902–1982), née Elizabeth Frances Thorndike, an American mathematician, daughter of Edward Thorndike
• Guillermo Thorndike (1940–2009), a Peruvian journalist and writer
• Helen Louise Thorndyke, pseudonym for the multiple authors of the Honey Bunch book series
• Herbert Thorndike (1598–1672), an English academic and clergyman
• Israel Thorndike (1755–1832), an American sailor, merchant, and politician
• John Thorndike (settler) (1611/12–1668), one of the founders of the Massachusetts Bay Colony, brother of Herbert Thorndike
• John Thorndike, (b. 1942), an American writer
• Joseph J. Thorndike (1913–2005), an American editor and writer
• Lynn Thorndike (1882–1965), an American historian, brother of Ashley Horace Thorndike
• Robert L. Thorndike (1910–1990), an American psychologist, son of Edward Thorndike
• Robert M. Thorndike (born 1943), an American psychologist, son of Robert L. Thorndike
• Russell Thorndike (1885–1972), a British actor and novelist, brother of Sybil Thorndike
• Sybil Thorndike (1882–1976), a British actress
• W. L. Thorndyke, perpetrator of the Maggie Murphy hoax

Fictional characters

• Dr. Thorndyke, a fictional detective in novels by R. Austin Freeman
• Chris Thorndyke, a human boy in the Sonic X anime television series
• Key Thorndyke, fictional newspaper magnate in the 1948 film State of the Union (film)
• Peter Thorndyke, villain in the 1968 film The Love Bug
• Dr. Richard Thorndyke, main character in the 1977 film High Anxiety

Places

• Thorndike, Maine, a town in the United States

Other

• Kennedy–Thorndike experiment
• Thorndyke (TV series), a 1964 BBC television series