The teacher, from Glendale primary in the Pollokshields area of Glasgow, is said to be responding well to treatment and is expected to make a full recovery.
The Public Health Protection Unit of NHS Greater Glasgow and Clyde has launched an investigation into the case.
Health chiefs have written to the parents of any children who have been in close contact with the patient, offering screening to make sure that they are not infected as a precautionary measure.
They have also written to the parents of the other children in the school offering reassurance and advice.
The teacher is recovering at home.
Dr Gillian Penrice, consultant in public health medicine, NHS Greater Glasgow and Clyde, said: "The patient is being given the appropriate treatment and as a precautionary measure we are arranging to carry out screening of any students who have been in close contact with the patient."
Tuberculosis (TB) is a bacterial infection. It is spread by inhaling tiny droplets of saliva from the coughs or sneezes of an infected person.
It mainly affects the lungs but can spread to other parts of the body, such as the bones or nervous system.
Typical symptoms include a persistent cough, weight loss and night sweats.