The Royal Oman Police (ROP) arrested Neena Varghese at the coastal town of Sur, about 200 km east of Muscat.
The woman worked as a teacher at the Indian School in Sur.
"The lady is under arrest and her husband's body is in the police mortuary in Muscat," a spokesman for the ROP was quoted as saying by Gulf News.
According to a source the deceased was in an inebriated state when he was killed. The couple from India's southern state of Kerala often had fights over his habit.
People close to the family in Sur are now coordinating with the police and the Indian embassy to send the body back to India.
Efforts being are made to send the two daughters, aged 11 and 13, to India as the mother is in police custody and there is no one to look after them.