Over the past two decades DeLaSalle's enrollment has climbed, and the school now receives an average of 400 applications each year for ninth grade admission.

Then-Archbishop John Ireland helped raise money in the late 1800s to build the new Catholic secondary school in Minneapolis.

By 1907, an addition had been added to the original building, and in 1914, the Archdiocese, at Archbishop Ireland's direction, purchased the adjoining King property to provide space for eventual expansion.

By 1950, enrollment was growing significantly each year, so much so that ninth graders were being educated in a separate building at West 43rd Street and Wentworth Avenue in south Minneapolis.

The school's administration opened a new residence for the Christian Brothers in 1950, facing Grove Street on the back side of the DeLaSalle campus.

In order to meet emerging educational and facility needs for a growing student body, in 2014 the DeLaSalle Board of Trustees authorized the construction of a new building.

In the Strategic Plan of 1993 the school focused its curriculum only on college preparatory classes, in large part to maximize resources that could be available for financial assistance for families.

The largest activities in terms of participation are theatre (six productions each year), music (both vocal and instrumental programs), and Lasallian "Campus" Ministry.

DeLaSalle students have succeeded in other programs not directed by the MSHSL, including competitive cheer (eight state titles), Quiz Bowl (eleven straight years qualifying for the National Championships), and musical theatre (20 group or individual awards earned in the annual Spotlight Program of the Hennepin Theatre Trust in 2017).

DeLaSalle is a member of the Tri-Metro Conference, a mix of private and public high schools throughout the Twin Cities that sponsors competitions, leadership programs, and other collaborative activities.