Ciel (meaning sky in French) may refer to:
- Ciel, a tincture in heraldry also called bleu celeste or celeste (sky-blue)
- Ciel (beverage) a bottled water brand owned by The Coca-Cola Company
- Ciel (company) the video game developer responsible for the visual novel After...
- Ciel, Saône-et-Loire, a commune of the Saône-et-Loire département, in France
- Center for International Environmental Law
- CIEL UK, (Le Centre International d'Etudes Liturgiques-UK)
- CIEL-FM, radio station in Quebec, Canada.
- CIEL (band), a local band in the Philippines.
- Fiction
- Ciel (Tsukihime) a vampire hunter in the visual novel, anime and manga Tsukihime, as well as the game Melty Blood
- Ciel (video game character) is the name of a main female character in the Mega Man Zero games
- Ciel Phantomhive, a fictional character in the manga and anime Kuroshitsuji