The history of the Sunnylea neighbourhood revolves around Alexander Thompson who purchased two hundreds acres of land in this area in 1803, after his discharge from the Kings Rangers.

Alexander Thompson lived in a distinguished residence, just south of Bloor Street at Royal York Road that was known as "Rose Bank Cottage." His son Archibald lived in a country Georgian farmhouse just to the south of his father, that was called "Spring Bank Cottage." Spring Bank Cottage is still standing today at 7 Meadowcrest Road.

The Thompson property was renowned for its apple, cherry, pear and plum orchards. In the latter part of the 1800's the Thompson's were joined in Sunnylea by families who cultivated thriving market gardens filled with fruits and vegetables. A handful of these old Sunnylea farmhouses are still standing both on Prince Edward Drive and on Islington Avenue.

In 1907, the first Sunnylea School - a two room white brick schoolhouse - was built on Prince Edward Drive. Edna G. Whitworth, a pupil at the school won a contest in coming up with the Sunnylea name which also became the name of this community.

Sunnylea's old farms were subdivided in the 1930's and 40's, when the present day neighbourhood was developed. The influx of new families to this community led to the opening of the second Sunnylea school in 1942.