Wallinska skolan or Wallinska flickskolan, was a girls' school in Stockholm, Sweden. Active from 1831 to 1939, it was one of the first five schools in Sweden to offer serious academic education and secondary education to female students. In 1870, it became the first gymnasium for females in Sweden, and in 1874, it became the first girls' school that was permitted to administer the Studentexamen to female students.

Single-sex education, also known as single-gender education and gender-isolated education, is the practice of conducting education with male and female students attending separate classes, perhaps in separate buildings or schools. The practice of single-sex schooling was common before the 20th century, particularly in secondary and higher education.