The history of Valley Catholic School dates to 1886 and the founding of the Community of the Sisters of St. Mary of Oregon, the first women's religious order to be established in Oregon.

In 1902, at the request of Archbishop William H. Gross, the religious community voted to open a school on Tualatin Valley Highway, west of Beaverton. The school, originally called St. Mary's Academy, served boys and girls. It opened its doors in January 1903.

Several years later, the Sisters opened a dormitory, and St. Mary's Academy became an all-girls school and was renamed St. Mary's Institute. In 1930, it was renamed again, becoming St. Mary of the Valley.

A groundbreaking for the current school was held on May 27, 1968. On December 1, 1969, classes were held in the new building for the first time.

In 1991, the school once again welcomed boys as well as girls, and St. Mary of the Valley High School and Middle School officially became Valley Catholic School. Enrollment has grown from 210 high school students in 1969 to 494 middle and high school students for the 2007–2008 school year.

 
 During the 2003-2004 school year, the SSMO Campus Schools celebrated their Centennial -- 100 years of educational excellence through faith and action.