Marumakkathayam was a system of matrilineal inheritance prevalent in Malabar which is the northern part of the present Kerala State in India. Under the Marumakkathayam system of inheritance, descent and succession of property was traced through females. Marumakkathayam literarily means inheritance by sister's children (as opposed to sons and daughters). The word ‘Marumakkal’ in Malayalam means nephews and nieces. Some scholars believe that the matrilineal system was the direct result of some system of polyandry that once existed in the area and that descent through females resulted from uncertain paternity.

Under the matrilineal system the joint family is known as Tarawad and it formed the nucleus of society in Malabar. This customary law of inheritance was codified by the Madras Marumakkathayam Act of 1932. This system of inheritance was abolished by The Joint Family System (Abolition) Act of 1975 by the Kerala State Legislature. Some Muslim families in Malabar and the people of Lakshadweep continue to follow this custom as the Abolition Act applies only to Hindus.