Naturally, Shi‘i Islam first started in the Hijaz (presently known as Saudi Arabia) amongst the companions of the Prophet. Reference to the Islamic historical and biographical works shows that the list of the Shi‘a pioneers among the companions of the Prophet includes the following well- known bani Hashim (offspring of Hashim, great-grandfather of the Prophet Muhammad): ‘Abdullah b. al-‘Abbas, al-Fadl b. al-‘Abbas, ‘Ubaydillah b. al-‘Abbas, Qiththam b. al- ‘Abbas, ‘Abd al-Rahman b. al-‘Abbas, Tamam b. al-‘Abbas, Aqil b. Abi Talib, Abu Sufyan b. al-Harth b. ‘Abd al- Mutallib, Naufil b. al-Harth, ‘Abdullah b. Ja‘far b. Abi Talib, ‘Awn b. Ja‘far, Muhammad b. Ja‘far, Rabi‘at b. al-Harth b. ‘Abd al-Mutallib, al-Tufayl b. al-Harth, al-Mughayrat b. Nawfil b. al-Harith, ‘Abdullah b. al-Harth b. Nawfil, ‘Abdullah b. Abi Sufyan b. al-Harth, al-‘Abbas b. Rabi‘at b. al-Harth, al-‘Abbas b. ‘Utbah b. Abi Lahab, ‘Abd al-Mutallib b. Rabi‘at b. al-Harth, Ja‘far b. Abi Sufyan b. al-Harth.
The list of Shi‘a among those companions of the Prophet who were not bani Hashim includes: Salman, Miqdad, Abu Dharr, ‘Ammar b. Yasir, Hudhayfah b. al-Yaman, Khuzaymah b. Thabit, Abu Ayyub al-Ansari, Abu al- Haytham Malik b. al-Tihan, Ubayy b. Ka‘b, Qays b. Sa‘d b. ‘Ubadah, ‘Adiy b. Hatam, ‘Ubadah b. al-Samit, Bilal al- Habashi, Abu Rafi‘, Hashim b. ‘Utbah, ‘Uthman b. Hunayf, Sahl b. Hunayf, Hakim b. Jibillah al-‘Abdi, Khalid b. Sa‘id b. al-‘Aas, Ibn Husayb al-Aslami, Hind b. Abi Halah al- Tamimi, Ju‘dah b. Hubayrah, Hujr b. ‘Adiy al-Kindi, ‘Amr b. al-Hamq al-Khuza‘i, Jabir b. ‘Abdullah al-Ansari, Muhammad b. Abi Bakr (the son of the first Caliph), Aban b. Sa‘id b. al-‘Asi, and Zayd b. Sauhan.1
1 For example, see Buhuth fi al-Milal wa al-Nihal by J. Subhani, vol. 6, pp. 109 & 110. Sayyid Ali al-Madani (d. 1120 A.H) in his Al-Darjat al-Rafi‘at fi Tabaqat al-Shi‘a al-Imamiyah mentions names of 69 Companions of the Prophet who were Shi‘a. Sayyid ‘Abd al-Husayn Sharaf al-Din (1377 A.H) in his Al-Fusul al-Muhimmah fi Ta’lif al-Ummah mentions names of more than two hundred Companions of the Prophet Muhammad who were Shi‘a. They are listed in an A-Z order starting with Abu Rafi‘ and ending with Yazid b. Hautharah al-Ansari. Yousuf b. ‘Abdullah (d. 456 A.H) in his Al-Isti‘ab, Ibn al-Athir in his Usd al-Ghabah and Ibn Hajar (d. 852 A.H) in his Al-Isabah are some of the non-Shi‘a scholars who have mentioned some of the Shi‘a pioneers.
Disovering Shi’i Islam Mohammad Ali Shomali 9th edition