Sangita Vithal, 49, was found dead in the kitchen of her Laudium home on Monday evening, the Pretoria News wrote.
Vithal had been a teacher at Andrew Anthony Primary School for 10 years.
She had been hit on the right side of her head with a blunt object.
Her handbag and cellphone were found in her car which had been left open in the driveway.
The police also said that there appeared to be signs of a struggle in various rooms in the house but nothing appears to have been stolen.
Vithal lived with her parents. Just hours before her death they left for a pilgrimage in India. They are on their way back to South Africa.