Ann Maguire, 61, was stabbed in front of about 30 pupils at Corpus Christi Catholic College in Leeds, about 175 miles (280 km) north of London, shortly before noon on Monday, and was pronounced dead in hospital.
Maguire, a mother of two who taught Spanish and religious education, had worked at the school for nearly 40 years and was due to retire this summer.
A teenager, who cannot be named for legal reasons, was arrested after her murder and charged on Wednesday with murder. "We have concluded that there is sufficient evidence to charge this youth with the murder of Ann Maguire and that it is in the public interest to do so," Peter Mann, head of the local Crown Prosecution Service (CPS), said in a statement.
The death has shocked Britain where violence in schools is rare. It comes a week after British media reported that from 2011 and 2013, some 1,000 school children were caught on school premises with lethal weapons such as guns, knives, axes and hammers.
Tributes for Maguire flowed from across the country while those who knew her laid flowers and cards outside the school. "My thoughts are with the family of Anne Maguire, as well as the staff and pupils of Corpus Christi school, where she was stabbed to death," Prime Minister David Cameron tweeted.
Prosecutors said the 15-year-old charged with her murder would appear at a Leeds youth court on May 1 and at Leeds Crown Court for a bail hearing the next day.
Maguire was said to be the first school teacher to be killed by a student since Philip Lawrence, a London headmaster, who was stabbed at the gates of his senior school in 1995.
The worst-ever attack on a school in Britain was at the Dunblane Primary School in Scotland in March 1996 when Thomas Hamilton, 43, entered the school armed with four handguns, killing 16 children and one adult before committing suicide.