The area where Koroit is now situated, was originally inhabited by the Peel Whurrong Aborigines. The name Koroit is said to be from an indigenous phrase, however the meaning is not known.
The first Europeans settled in the district in 1837. The rich volcanic soil attracted a number of large landholders to the area, who imported Irish labourers to work on their properties. This was a particularly attractive proposition to many Irish, as the potato famine was decimating their own country and the areas green rolling hills were reminiscent of their home.
The foundation stone of St Patrick's Convent was laid on the 6th May 1906, with over 2000 spectators. The building was built of Warrnambool sandstone at an estimated cost of 5,000 pounds. On the 1st of October 1907 the convent was blessed and opened (some claim with a crowd 5,000 strong), amid numerous speeches a plea for funds was made as there was still a debt of 3,255 pounds. The convent was built with 28 rooms to house 20 nuns.
The first 8 Good Samaritan nuns arrived in October 1907 and were kept busy teaching at various schools around the area. The downstairs area of the convent was used as a secondary school, with classrooms in the now Billiard room and Breakfast rooms, as well as music lessons taught to non-catholics in the office.
By 1972 all parish children were being taught at St Patrick's primary school, across the road, with secondary students completing their education in Warrnambool. The convent was closed at the end of 1972 and was sold to a group of Melbourne schools to be used as a school camp/hostel.
For 30 years the hostel provided a base for students to visit the area, it was also used for the Lake Music School each year.
In 2003 Kim and Craig Fraser purchased the convent, it was in an advanced state of disrepair. They did an amazing job, restoring the magnificant property and modernizing the infrastructure of wiring, heating, plumbing and new bathrooms.