Taking its name from the historic Eynesbury House on Old Belair Road, Kingswood, the college was established in 1990. Eynesbury House remains an icon which people still connect with the college, however in January 1996 Eynesbury moved to a larger campus in the heart of the city on Franklin Street due to outgrowing the Kingswood Campus. Eynesbury remained a two-campus school until the end of 2001 when all classes were consolidated at the Franklin Street campus.

From 2001 until 2010 Eynesbury Senior College co-existed with the English Language School (ELICOS) on the Franklin Street Campus. However, in 2010 the ELICOS campus and the Foundation Programs moved to Coglin Street.

Eynesbury Senior College is one of Adelaide’s oldest private senior secondary college for Years 10, 11, and 12, specialising in preparing students for university and life beyond the classroom. It also offers a Year 9 Early Entry Program into Year 10 studies for students as well.