Supplication of Kumayl (Arabic: دعاء کميل) is a supplication narrated by Kumayl b. Ziyad al-Nakha'i from Imam Ali (a).

This supplication contains great and noble messages for knowing God and requests for forgiveness of sins. Al-Allama al-Majlisi considered the supplication of Kumayl best of supplications. This supplication is among common supplications Shia recite on the eve of 15th of Sha'ban and eves of Friday.