Crucifixion is a form of slow and painful execution in which the victim is tied or nailed to a large wooden cross and left to hang until dead. It is principally known from antiquity, but remains in occasional use in some countries.

The crucifixion of Jesus is a central event in Christianity, and the cross (sometimes depicting Jesus nailed onto it) is the main religious symbol for many Christian churches.

Crucifixion was often performed to terrorize and dissuade its witnesses from perpetrating particularly heinous crimes. Victims were left on display after death as warnings to others who might attempt dissent. Crucifixion was usually intended to provide a death that was particularly slow, painful (hence the term excruciating, literally "out of crucifying"), gruesome, humiliating, and public, using whatever means were most expedient for that goal. Crucifixion methods varied considerably with location and time period.

The Greek and Latin words corresponding to "crucifixion" applied to many different forms of painful execution, from impaling on a stake to affixing to a tree, to an upright pole (a crux simplex) or to a combination of an upright (in Latin, stipes) and a crossbeam (in Latin, patibulum