Source: Elections Canada

Lanark—Frontenac is a federal electoral district that was introduced for the 2025 federal election. Its designation and boundaries supersede those of Lanark–Frontenac–Kingston, following a redistribution undertaken by Elections Canada to address evolving population trends.

The riding includes all of Lanark County, covering towns such as Perth, Carleton Place, and Smiths Falls. It also encompasses the portion of Frontenac County located north of Highway 401, including rural areas surrounding Kingston.

According to the 2021 census, 90.5% of the population is white, and Indigenous peoples represent 6.6%. English is spoken by 92% of residents, with French spoken by 3.3%. Christianity is the most common religion at 59.1%, yet almost 40% of people have no religious ties. In 2020, the median income was $44,400, and the average income reached $54,150.

Consists of:

1. the towns of Carleton Place, Perth and Smiths Falls; and township of Mississippi Mills (Almonte, Pakenham, Clayton, Blakeney and Appleton)
2. the townships of Beckwith, Central Frontenac, Drummond/North Elmsley, Lanark Highlands, Montague, North Frontenac, South Frontenac and Tay Valley.