In Christian theology, the Harrowing of Hell (Latin: Descensus Christi ad Inferos; Greek: Ἡ εἰς ᾍδου κάθοδος τοῦ Χριστοῦ – "the descent of Christ into Hell" or "Hades") is the period of time between the Crucifixion of Jesus and his resurrection. In triumphant descent, Christ brought salvation to the souls held captive there since the beginning of the world.

Christ's descent into the world of the dead is referred to in the Apostles' Creed and the Athanasian Creed (Quicumque vult), which state that he "descended into the underworld" (descendit ad inferos), although neither mention that he liberated the dead. His descent to the underworld is alluded to in the New Testament in 1 Peter 4:6, which states that the "good tidings were proclaimed to the dead". The Catechism of the Catholic Church notes Ephesians 4:9, which states that "[Christ] descended into the lower parts of the earth", as also supporting this interpretation. These passages in the New Testament have given rise to differing interpretations. The Harrowing of Hell is commemorated in the liturgical calendar on Holy Saturday.

According to The Catholic Encyclopedia, the story first appears clearly in the Gospel of Nicodemus in the section called the Acts of Pilate, which also appears separately at earlier dates within the Acts of Peter and Paul. The descent into Hell had been related in Old English poems (e.g. Christ and Satan) connected with the names of Cædmon and Cynewulf. It is subsequently repeated in Ælfric of Eynsham's homilies c. 1000 AD, which is the first known inclusion of the word harrowing. Middle English dramatic literature contains the fullest and most dramatic development of the subject.

As a subject in Christian art, it is also known as the Anastasis (Greek for "resurrection"), considered a creation of Byzantine culture and first appearing in the West in the early 8th century.

The Old Testament view of the afterlife was that all people when they died, whether righteous or unrighteous, went to Sheol, a dark, still place. Several works from the Second Temple period elaborate the concept of Sheol, dividing it into sections based on the righteousness or unrighteousness of those who have died.

The New Testament maintains a distinction between Sheol, the common "place of the dead", and the eternal destiny of those condemned at the Final Judgment, variously described as Gehenna, "the outer darkness", or a lake of eternal fire.

The Greek wording in the Apostles' Creed is κατελθόντα εἰς τὰ κατώτατα (katelthonta eis ta katōtata), and in Latin is descendit ad inferos. The Greek τὰ κατώτατα (ta katōtata, 'the lowest') and the Latin inferos ('those below') may also be translated as "underworld", "netherworld", or "abode of the dead".

The realm into which Jesus descended is called Hell, in long-established English usage, but is also called Sheol or Limbo by some Christian theologians to distinguish it from the Hell of the damned. In Classical mythology, Hades is the underworld inhabited by departed souls, and the god Pluto is its ruler. Some New Testament translations use the term "Hades" to refer to the abode or state of the dead to represent a neutral place where the dead awaited the death, burial, and resurrection of Jesus.