Banu Lam is an Arab tribe of central Arabia and southern Iraq.

The tribe claims descent from the ancient Arab tribe of Tayy, and dominates western Nejd (the region between Medina and al-Yamama) before the fifteenth century.

The tribe splits into three main Bedouin (nomadic) groups: the Fudhool, the Al Kathir, and the Al Mughira, and Al-Dhafeer.

The Bani Lam tribes gradually leave Nejd, settling mostly in southern Iraq, where they convert from Sunni to Shi'a Islam largely just before or during the nineteenth century.

Many clans from Banu Lam, however, remain in Nejd as settled townspeople.

The Fudhool are the last of Bani Lam to leave Nejd, in the eighteenth century.