can refer to:
- Term meaning "gradual change" (from the Greek [klīnein], "to lean")
- Cline (population genetics), a gradual change of a character or feature (phenotype) in a species over a geographical area.
- "Cultural cline" is a gradual change of a cultural characteristic or feature over a geographical area.
- Thermocline, a layer within a body of water or air where the temperature changes with depth.
- cline (linguistics) where the term cline refers to a list of words dealing with the same concept, arranged in order of intensity. For example a list could be made with words like "freezing", "cold", "cool", "tepid", "warm", "hot", and "scorching".
- Antonov An-32, NATO reporting name of Cline
Of various etymology, primarily from German Klein, "small, insignificant".
- Adrian Cline, American runner
- Catherine Ann Cline (1927-2005), American historian and author
- Dylan and Jordan Cline (b. 2003), twin American child actors
- Edward Cline, American screenwriter and director
- Eric Cline (b. 1955), Canadian politician
- Ernest Cline (b. 1972), American comedian and screenwriter
- Gene Clines (b. 1946), American baseball player
- Hoyt Franklin Clines (d. 1994), American murderer
- Isaac Cline (1861-1955), American meteorologist
- Kristi Cline (b. 1980), Playboy playmate
- Leticia Cline (b. 1978), American model and wrestling personality
- Martin Cline (b. 1934), American geneticist
- Melanie Cline (b. 1975), American BMX racer
- Nels Cline (b. 1956), American guitarist and composer
- Ollie Cline (1925-2001), American football player
- Patsy Cline (1932-1963), country music star
- Reginald Cline-Cole, Sierra Leonean professor of developmental geography
- Russell Cline, American currency trader and conman
- Sperry Cline (d. 1964), Canadian frontier policeman
- Ty Cline (b. 1939), American baseball player
- Victor Cline, prominent American psychoanalyst