A skyline is the overall or partial view of a city's buildings and structures against the sky. It can also be described as the artificial horizon that a city's overall structure creates. Skylines serve as a kind of fingerprint of a city, as no two skylines are alike. For this reason news and sports programs, television shows, and movies often display the skyline of a city to set location. The Sky Line of New York City was a new term in 1896, when it was the title of a color lithograph by Charles Graham for the color supplement of the New-York Journal.

Paul D. Spreiregen, FAIA, has called a skyline "a physical representation [of a city's] facts of life ... a potential work of art ... its collective vista."