CEP or Cep may refer to:
Cephalonia or Kefalonia (Greek: Κεφαλονιά or Κεφαλλονιά), formerly also known as Kefallinia or Kephallenia (Κεφαλληνία), is the largest of the Ionian Islands in western Greece.
The cephalic index or cranial index is the ratio of the maximum width (bipareital diameter or BPD, side to side) of the head of an organism (human or animal) multiplied by 100 divided by its maximum length (occipitofrontal diameter or OFD, front to back).
A Cepheid variable (/ˈsɛfiːɪd/ or /ˈsiːfiːɪd/) is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude.
Cephalometric analysis is the clinical application of cephalometry. It is analysis of the dental and skeletal relationships of a human skull.
A cephalic presentation or head presentation or head-first presentation is a situation at childbirth where the fetus is in a longitudinal lie and the head enters the pelvis first; the most common form of cephalic presentation is the vertex presentation where the occiput is the leading part (the part that first enters the birth canal).