It was created in 1841 and was partially based on the previous electoral district of the same name for the former Legislative Assembly of Lower Canada.

The Montreal County district initially included a significant portion of the city, as a result of the boundaries drawn by the Governor General, Lord Sydenham, as part of his goal to increase the voting strength of voters of British background, at the expense of the francophone Canadiens.

[5] As part of his plan to ensure that goal, he drew the boundaries of the new Montreal district to favour the voters of British background, who generally favoured the union, and to exclude francophone Canadien voters, who generally opposed the union.

The result was an ethnic and linguistic gerrymander, which effectively disenfranchised francophone some of the voters of Montreal in the 1841 election.

[8][9][10] Montreal County was abolished by a redistribution statute enacted in 1853, which took effect in the next general elections in 1854.