It encompasses a portion of Ontario previously included in the electoral districts of Markham—Unionville and Oak Ridges—Markham.

[4] Markham—Stouffville was created by the 2012 federal electoral boundaries redistribution and was legally defined in the 2013 representation order.

Helena Jaczek has represented the riding since the 2019 federal election.

The territory of the riding (map[5]) consists of part of the Regional Municipality of York: (a) the Town of Whitchurch-Stouffville; and (b) the part of the City of Markham lying easterly of a line described as follows: commencing at the intersection of the northerly limit of Markham with Highway 48; then southerly along Highway 48 to 16th Avenue; then westerly to McCowan Road; then southerly to Highway 407; then easterly along Highway 407 to the Rouge River; then generally southeasterly along Rouge River to the southerly limit of Markham.

[6] According to the 2021 Canadian census[7] Ethnic groups: 36.0% White, 27.7% Chinese, 19.0% South Asian, 3.7% Black, 3.6% Filipino, 1.1% Arab, 1.1% West Asian Languages: 51.2% English, 12.7% Cantonese, 7.1% Mandarin, 4.9% Tamil, 1.6% Italian, 1.6% Urdu, 1.4% Tagalog, 1.0% Gujarati Religions: 47.0% Christian (22.3% Catholic, 4.3% Christian Orthodox, 2.6% Anglican, 2.2% United Church, 1.3% Baptist, 1.1% Presbyterian, 13.2% Other), 10.2% Hindu, 6.9% Muslim, 2.4% Buddhist, 1.0% Sikh, 31.5% None Median income: $43,200 (2020) Average income: $59,800 (2020) This riding has elected the following members of Parliament: