The focal point of the Martorana’s decoration is the dome, consistent with Byzantine tradition and the church’s original central plan layout. The dome’s decorative scheme is a simplified, more intimate version of that of the nearby Palatine Chapel.

• A seated Christ Pantocrator — head backed by an inscribed cross halo and flanked by the letters ΙCΧC, a Greek Christogram for “Jesus Christ” — occupies the center of the dome.
• A white ring around the Pantocrator image holds an inscription (see image below) that quotes, in Greek, from John 8:12: “I am the light of the world. Whoever follows me will never walk in darkness, but will have the light of life.”. It matches the inscription that appears in the open books held by the apse Pantocrators at Cefalù Cathedral, the Palatine Chapel and Monreale Cathedral. Note, however, that the Latin translation held by the apse Pantocrators has been omitted.
• Four winged archangels — Michael, Gabriel, Raphael and Uriel — symbolizing Christ’s divine incarnation in heaven, comprise the balance of the dome’s decoration. They are depicted bent over, with long torsos and extremely short legs. While the distorted proportions might reflect the mosaicists’ desire to symbolically convey their extreme deference to the Pantocrator, it might also be attributable to a poor adaptation from an earlier prototype in which the angels were kneeling rather than standing.
• Interestingly, around the edge of the base of the dome (at the feet of the archangels, and virtually invisible from the floor of the church) is a wooden frieze with an inscription of a Byzantine hymn in Arabic translation.
• Eight prophets — each standing with a single arm raised, as if directing beholders to the Pantocrator above — are wedged between the squinches and round-arched windows. The mortal counterparts of the archangels, they symbolize Christ’s human incarnation on earth.
• The four evangelists — Matthew (in northeastern corner), Mark (in northwestern corner), Luke (in southwestern corner), and John (in southeastern corner) — sit in the squinches.
• Just below the Evangelists, on the eastern side, is a depiction of the Annunciation: Gabriel hovers on the left, announcing to the Virgin Mary (seated on the right) that she will conceive and become the mother of Jesus. On the western side is the Presentation of the Child at the Temple: Mary holds the baby Jesus on the left, handing him over to Simeon, the Jewish High Priest, on the right.