The Tigard-Tualatin School District (23J) is a school district serving part of the suburban Portland metropolitan area in Oregon including all or portions of the cities of Tigard, Tualatin, Durham, and King City, as well as most of the unincorporated communities of Metzger and Bull Mountain.

Fowler and Twality Junior High Schools covered grades 7–9.

When Tualatin High opened, new school attendance boundaries were drawn; most students at Twality would attend Tualatin High and most students at Fowler would attend Tigard High.

Students living in certain areas were given the option of attending either high school.

Its boundary includes most of the municipalities of Tigard and Tualatin, all of Durham and King City, the majority of the census-designated places of Bull Mountain and Metzger, and small sections of Lake Oswego and Rivergrove.