St. John's South—Mount Pearl (French: St. John's-Sud—Mount Pearl; formerly St. John's South) is a federal electoral district in Newfoundland and Labrador, Canada, that has been represented in the House of Commons of Canada since 2004.

Ethnic groups: 99.2% White Languages: 98.7% English Religions: 52.8% Catholic, 42.4% Protestant, 3.6% no affiliation Average income: $25 379 The district includes the south end of the City of St. John's, the City of Mount Pearl, and the Town of Petty Harbour-Maddox Cove.

As of the 2012 electoral redistribution, 5% of this riding would be moved to St. John's East, and it would gain 3% from Avalon.

[2] The redefined St. John's South—Mount Pearl had its boundaries legally defined in the 2013 representation order which came into effect upon the call of the 42nd Canadian federal election, scheduled for 19 October 2015.

This riding has elected the following members of Parliament: Results of the Canadian student vote.