Muddathir (; transliterations vary) is an Arabic given name from Al-Muddaththir, a name of Muhammad mentioned in the Qur'an. It may refer to:
Muddathir Abdel-Rahim (born 1932), Sudanese academic and activist Mudather El Tahir (born 1988), Sudanese footballer Mudathir Yahya (born 1996), Tanzanian footballer
See also Muzzammil (name) Mudassar Mubashir Al-Muddaththir, a surah of the Quran