Zayd ibn Amr (died 605) was a monotheist who lived in Mecca shortly before Islam.
He was the son of Amr ibn Nufayl, a member of the Adi clan of the Quraysh tribe. Zayd's mother had previously been married to his grandfather, Nufayl ibn Abduluzza, so her son from this marriage, al-Khattab ibn Nufayl, was at the same time Zayd's maternal half-brother and paternal half-uncle.
Zayd married Fatima bint Baaja from the Khuza'a tribe, and their son was Sa'id ibn Zayd. A subsequent wife, Umm Kurz Safiya bint al-Hadrami, bore his daughter Atiqa.
Zayd became disillusioned with the traditional religion of Arabia, for the stone that that the people worshipped "could neither hear nor see nor hurt nor help" and "the worship of stone or hewn wood is nothing." He pledged with three friends that they would seek the true religion of Abraham, which they called al-Hanafiya. The other three men eventually converted to Christianity.
Zayd travelled to Syria to question both Jews and Christians about their beliefs, but he was not happy with the answers of either group. According to later Muslim historians, he had "the religion of Abraham, following the natural form" and "worshipped Allah alone with no partner." Amir ibn Rabia, an ally of Zayd's brother al-Khattab, later said that Zayd had told him that he believed in the future coming of a prophet.
Three points of Zayd's religious beliefs were agreed. First, he did not worship idols and he rebuked the Quraysh for doing so. Asma bint Abi Bakr heard him declaring outside the Kaaba: "O Quraysh, none of you is following Abraham's religion except me." He composed this poem:
Second, he modified his diet. He did not eat carrion, blood or anything that had been slaughtered for an idol. He told the Quraysh: "Allah has created the sheep and he has sent the rain and the grass for it; yet you don't mention Allah's name when you slaughter it."
Third, he opposed infanticide. He rescued infant girls who were about to be buried alive and brought them up in his own house. When the girls had grown older, he would offer their fathers a choice between taking their daughters back or leaving them to be supported at Zayd's expense.
Zayd's wife Safiya disliked his travels to Syria. Whenever she saw him preparing for a journey, she reported it to al-Khattab, who would reproach Zayd for abandoning their religion. Zayd did not bother to explain himself to al-Khattab, but he rebuked Safiya for trying to humiliate him.
Al-Khattab harassed Zayd so severely that Zayd was forced to leave the city. He spent the last few years of his life in the mountain-caves surrounding Mecca. Al-Khattab then instructed the "young irresponsible men of the Quraysh" to ensure that Zayd could never enter the city again. Whenever Zayd tried to enter in secret, al-Khattab's men drove him out again.
In 605 Zayd was returning from a trip to Syria. Before he reached Mecca, in the country of Lakhm, he was murdered. Waraka ibn Nawfal is said to have composed an elegy for him.