Al-Wathiq I (Arabic: أبو إسحاق إبراهيم الواثق, Abū Isḥāq Ibrāhīm al-Wāṯiq; died after 1341) was the fourth Abbasid caliph seated in Cairo under the Mamluk Sultanate between 1340 and 1341.

His grandfather al-Hakim I was preoccupied with playing, and he turned to the friendship of the erals, so he changed his mind and entrusted to his son Abu Rabee Suleiman, who spoke about him. Abu Rabee Suleiman took the order and was named as al-Mustakfi I. Ibn Qalawun, and this led to the split between the two after they were like brothers and catch the Sultan of the Caliph al-Mustakfi and his family and his family to Qus, where he remained until he died in 740 AH and was entrusted before his death to his son Ahmed. As for Sultan al-Nasir Ahmad ibn Qalawun, the Caliph denied this allegiance to Ibrahim in the name of the believer in God. He did not look at the era of the Muqtafi. When the death came, he regretted what he did. Al-Nasir Muhammad ibn Qalawun died in Dhu al-Hijjah in 1344 (741 AH) after he recommended the abdication of the caliph.

• "Biography of Al-Wathiq I" (in Arabic). Islampedia.com. Archived from the original on 2008-06-11.

• Garcin, Jean-Claude (1967). "Histoire, opposition, politique et piétisme traditionaliste dans le Ḥusn al Muḥādarat de Suyûti" [History, opposition, politics and traditionalistic pietism in Suyuti's Ḥusn al Muḥādarat] (PDF). Annales Islamologiques (in French). 7. Institut Français d'Archéologie Orientale: 33–90. doi:10.3406/anisl.1967.909. S2CID 259055409. Archived from the original (PDF, 14.62 MB) on 2011-07-24. Retrieved 2010-07-22.
• Holt, P. M. (1984). "Some Observations on the 'Abbāsid Caliphate of Cairo". Bulletin of the School of Oriental and African Studies. 47 (3). University of London: 501–507. doi:10.1017/s0041977x00113710. JSTOR 618882. S2CID 161092185.