Mr Williamson said he supports headteachers to take any action necessary when faced with persistent bad behaviour including detentions, suspensions or expulsions.
Writing in The Telegraph, he said after a year of pandemic-induced disruption for children, maintaining good discipline in the classroom is an “absolute must”.
“This longed-for return to the classroom will give them the structure and order they desperately need, where they feel safe and ready to learn,” he said.
“Although remote learning was a tremendous success in terms of enabling children to carry on with their lessons from home, the lack of regular structure and discipline will inevitably have had an effect on their behaviour.”
He said that while technology has helped children to learn during lockdowns, it is “now time to put the screens away, especially mobile phones”.
Mr Williamson said he is not opposed to the “controlled use” of a tablet or laptop in class, where it is being used for educational purposes.
But he added that he “firmly believes” mobile phones should not be used during the school day, adding that he “will be backing headteachers that implement such policies”.
He said: “Outside the classroom, the use of mobile phones distracts from healthy exercise and good old-fashioned play.
“Worse, it acts as a breeding ground for cyberbullying, and the inappropriate use of social media sites – such as anonymous Instagram accounts, where students are ranked on their appearance – can heighten insecurities, damage mental health and encourage harassment.”