Subay' (Arabic: سبيع, also spelle Sbay', Sbei', and Subei) are a Sunni Muslim tribe of central Saudi Arabia. The tribe is of North Arabian (Adnanite) stock, and traces its lineage to the large, ancient tribe of Banu 'Amir, also known as 'Amir ibn Sa'sa'a, who came to dominate Nejd in the medieval period.