A major milestone has been reached in the creation of a new, world-class high school in Adelaide's north-east.

Construction of the $84.4 million Morialta Secondary College began with the demolition of ageing buildings on the site that were part of the former Norwood Morialta Middle School Campus.

Over the duration of the staged build, they'll be replaced by a state-of-the-art contemporary design, from architects Thompson Rossi and Brown Falconer, that includes flexible learning spaces, a performing arts centre, library, gallery, gymnasium and cafe. 

The new school is being built by Sarah Constructions who have also delivered three of the state's newest schools at Whyalla, Angle Vale and Aldinga. 

Morialta Secondary College Principal, Roley Coulter, said "It's very exciting to see the start of construction work. We can't wait to welcome our first students."

The school’s scheduled to accept enrolments for year 7 in 2023 and when fully operational will grow to having 1200 students from years 7 to 12..