Grace Marufu is already married to Mugabe under African traditional law that allowed him to take her as a junior wife while his first wife, Sally, was still alive. Sally Mugabe died in 1991 of a chronic kidney ailment. Marufu, 42, and Mugabe, 72, have a daughter, 9-year-old Bona, and a son, 7-year-old Robert Jr. Mugabe's only child by Sally died in infancy.
Archbishop Patrick Chakaipa, head of the Roman Catholic Church in Zimbabwe, confirmed that preparations were being made for a mid- August wedding. Mugabe's ruling Zimbabwe African National Union Patriotic Front was expected to make the event a gala national celebration.
Reports of a planned church wedding indicate Mr Mugabe has smoothed over differences with Catholic leaders who had criticized his relationship with Marufu.
Three journalists were convicted of "criminal defamation" for reporting last year that Mr Mugabe and Ms Marufu had been married in secret.