Loretto Abbey Catholic Secondary School

Loretto Abbey Catholic Secondary School (sporadically known as Loretto Abbey CSS, LACSS, Loretto Abbey, LAT, Loretto Abbey Toronto or The Abbey) is an all-girls Catholic secondary school in Hogg's Hollow neighbourhood of Toronto, Ontario, Canada. Established by the Loretto Sisters in 1847, it is one of Toronto's oldest educational institutions and is part of the Toronto Catholic District School Board (then the Metropolitan Separate School Board) since 1987.

Loretto Abbey operates on the non-semestered system offering Advanced Placement, academic and applied courses; approximately 85% of the school's courses are offered at the academic level, educating girls to university-entrance standards. The school offers co-operative education, extended French, Advanced Placement programmes and special education (resource and gifted).