The Ontario Secondary School Literacy Test (OSSLT) assesses whether students have acquired the literacy (reading and writing) skills expected by the Ontario Curriculum across all subjects up to the end of Grade 9. It is cross-curricular in that it links the literacy skills tested by the OSSLT to samples of overall and specific expectations in the Grades 7, 8, and 9 Ontario Curriculum policy documents.

It is created and scored by The Education Quality and Accountability Office (EQAO) of Ontario.