In classical Islamic law, a concubine was a slave-woman with whom her master engaged in sexual relations. Concubinage was widely accepted by Muslim scholars in pre-modern times. Most modern Muslims, both scholars and laypersons, believe that Islam no longer permits concubinage and that sexual relations are religiously permissible only within marriage.

Concubinage in the Muslim world was the practice of Muslim men entering into intimate relationships without marriage, with enslaved women, though in rare, exceptional cases, sometimes with free women. If the concubine gave birth to a child, she attained a higher status known as umm al-walad.