Amina bint Abdulhalim Nassar was executed in the northern province of Jawf for "practising witchcraft and sorcery," the ministry said in a statement carried by SPA state news agency.
Amnesty International said beheading took to 73 the number of executions in Saudi Arabia this year.
Rape, murder, apostasy, armed robbery and drug trafficking are all punishable by death under Saudi Arabia's Islamic sharia law. (AFP)
