Marwan ibn al-Hakam ibn Abu al-'As ibn Umayyah (623 – 7 May 685) is the fourth Umayyad Caliph, and the cousin of Uthman ibn Affan, who takes over the dynasty after Muawiya II abdicates in 684.

Marwan's ascension points to a shift in the lineage of the Umayyad dynasty from descendants of Abu Sufyan (the "Sufyanids") to those of Hakam (the "Marwanids"), both of whom are grandsons of Umayya (for whom the Umayyad dynasty is named).

Hakam is also the uncle of Uthman ibn Affan.