Introduction

Primary education, Intermediate education, and secondary education combined are sometimes referred to as K-12 (Kindergarten through Grade 12). Secondary schooling, known as high school, collegiate institute, école secondaire or secondary school, consists of different grades depending on the province in which one resides. Furthermore, grade structure may vary within a province or even within a school division; as to whether or not they operate middle or junior high schools.

Kindergarten programs are available for children in all provinces in Canada, and are typically offered as one year programs for students who turn five in that year. However, the provinces of Nova Scotia, the Northwest Territories, Ontario, and Quebec operate two-year kindergarten programs, with the first year beginning at the age of four. The names of these programs, provincial funding, and the number of hours provided varies widely. For example, the Department of Education in Nova Scotia refers to Kindergarten as Grade Primary.[67] Full day kindergarten programs are offered in all provinces except Alberta, Manitoba, Nunavut, Saskatchewan, and Yukon. Students in the Prairie provinces are not required by statute to attend kindergarten. As a result, kindergarten often is not available in smaller towns.

Since the 1940s, Ontario's kindergarten program consisted of two years, junior kindergarten for four-year-olds, and senior kindergarten for five-year-olds. At Francophone schools in Ontario, these programs are called Maternelle and Jardin.[68] In 2016, Nova Scotia began to implement a two-year kindergarten program (pre-primary, and primary), with provincial-wide service expected by 2020.[69] In 2017, the Northwest Territories introduced its junior kindergarten program throughout the territory.[58] Quebec offers heavily subsidized preschool programs and introduced an early kindergarten program for children from low-income families in 2013.

Grade 12 presently serves as the final grade in all provincial secondary curriculums, except Quebec, whose secondary schools ends after Secondary V/Grade 11 (age 16 by 31 December); after which, students who wish to pursue further studies may attend a post-secondary institution. Quebec is currently the only province where it treats Grade 12 as a part of the tertiary level of education. Grade 11 also served as the end of secondary education in Newfoundland and Labrador, until the province implemented Grade 12 in 1983. Conversely, from 1921 to 2003, Ontario's secondary curriculum lasted a year longer, with secondary schooling ending after Grade 13/Ontario Academic Credit (OAC). Grade 13 was reformed into OAC in 1988, and was offered in secondary schools until 2003, after which the grade was discontinued.

Students may continue to receive publicly-funded secondary schooling until the ages of 19 to 21 (the cut-off age for high school varies between provinces). Dependent on the province, those who are the age of majority may continue to attend a standard secondary school, or may be required to attend an adult high school.

Students of high school age who have received long-term suspensions or have been expelled, or are otherwise unable or unwilling to attend conventional schools may be offered alternative learning options to complete their secondary education, such as drop-in programs, night school, or distance/online classes. An increasing number of international students are attending pre-tertiary courses at Canadian high schools.