The ban, overturning centuries of tradition, comes after campaigning and education programmes by Unicef, the United Nations' children's programme, and anybody found practising circumcision on girls now faces up to five years in prison.
Unicef estimates that around 700,000 women, a quarter of the female population, have suffered some form of genital mutilation, normally carried out between early childhood and the age of 16.
Rite: Many see the practice as vital
Up to 100 million women may have been subjected to the practice worldwide, principally in parts of Africa, Asia and the Middle East.
Circumcision involves cutting away the external genitalia, the clitoris and labia minora. The vagina is often partially sewn up in a procedure performed without the use of anaesthetic.
Supporters of circumcision say it is a symbol of purification, a cultural rite of passage. But opponents, including US President Bill Clinton's wife Hilary, describe it as an extreme form of oppressing women.
The World Health Organisation estimates that thousands of women die from infections, haemorrhaging or during child birth because of mutilation.
Dozens of villages across Senegal have renounced the rite in the last year after being told of the health hazards it poses.
In October Togo banned female circumcision - backed by up to 10 years in prison for offenders.