'Amr ibn Al-Aas was a prominent member of the Banoo Sahm section of the Quraysh. His father Al-'Aas ib Waail was the chief of the Banoo Sahm and was a well to do merchant who commanded great influence among the Quraish of Makkah. When the Prophet of Islam (peace be upon him) announced his mission, Al-'Aas was one of the prominent members of the Quraish who pressed all their influence into service to oppose the Prophet (peace be upon him) and torture the Muslims. Hishaam a brother of 'Amr, however, accepted Islaam in the early years of the mission of the Prophet (peace be upon him), and in spite of the pressure of his father did not recant from Islaam. Hishaam was one of the Muslims to migrate to Abysinnia. 'Amr headed the delegation that the Quraysh sent to Abysinnia to prevail upon the ruler of Abysinnia to turn away the Muslims from his country. The mission failed and the ruler of Abysinnia refused to oblige the Quraysh. After the migration of the Holy Prophet to Madinah 'Amr took part in all the battles that the Quraish fought against the Muslims.
Amr ibn Al-'Aas (may Allah be pleased with him) came to the Prophet (peace be upon him) in Madinah one year and one month before the Conquest of Makkah. He embraced Islam and swore allegiance to the Prophet (peace be upon him) in return for having the Messenger of Allah (peace be upon him) supplicate for the forgiveness of all of his previous sins. In a hadeeth narrated upon the authority of 'Amr ibn Al-'Aas who said, narrating the story of how he embraced Islam,
"When Allah put Islam in my heart, I went to the Prophet (peace be upon him) in order to swear my allegiance to him. When (the Messenger of Allah ) extended his hand to me (to accept my pledge of allegiance) I said,
'O Messenger of Allah, I will not swear my allegiance to you until you seek forgiveness for me for all of my previous sins!'
The Messenger of Allah (peace be upon him) said, 'O 'Amr, do you not know that migration (from the land of the kuffaar to the land of the Muslims) wipes away all of the sins before it? O 'Amr, do you not know that Islam wipes away all of the sins before it?'"
After that the Messenger of Allah (peace be upon him) put him in command of a military operation to a place called Dhaat-us-Salaasil. The Messenger of Allah (peace be upon him) also used him for a mission in 'Omaan and he remained there until the Prophet (peace be upon him) died.
And in another hadeeth, narrated upon the authority of 'Uqbah ibn 'Aamir who said that the Messenger of Allah (peace be upon him) said: "The people have submitted (to Allah) but 'Amr ibn Al-'Aas has believed (in Allah)."
In another hadith, narrated upon the authority of Ibn Abee Malaikah who said that Talha ibn 'Ubayd-Allah said that he heard the Messenger of Allah (peace be upon him) say, "'Amr ibn Al-'Aas is from the righteous people of the Quraysh."
In addition, 'Amr ibn Al-'Aas was amongst the bravest of the Arabs and one of their most skillful champions (may Allah be pleased with him).