Julie Parkin, 39, was found dead at an address in Kirkwall Close, Hylton Castle, Sunderland, on Tuesday.
She taught at West Boldon Primary School. Head teacher Joanne Weightman said Mrs Parkin was "highly respected" and the school was "deeply shocked".
A 35-year-old man has been arrested on suspicion of murder and is being held in police custody.
Ms Weightman said: "We are deeply shocked and saddened by this tragic news.
"Mrs Parkin was a highly valued and respected member of staff who was popular with both pupils and colleagues.
"We are working with the local authority to offer support to students and staff and will  co-operate fully with any police investigation."
A primary school head teacher has spoken of her shock after a teacher at her school was found stabbed to death.