The township lies within the Ottawa River basin, having an elevation of 210 metres (690 ft) near the Quinze rapids to 336 metres (1,102 ft) in its north-eastern part.

[4] In addition to the main namesake village, the township also includes the hamlet of Paquin (47°37′59″N 79°18′51″W / 47.63306°N 79.31417°W / 47.63306; -79.31417).

In 1904, the geographic township of Guérin was proclaimed, named after James John Edmund Guerin, while the settlement was called Lalemant, in honour of Gabriel Lalemant.

The Lalement Post Office opened in 1908, and that same year, the parish of Saint-Gabriel-de-Guérin was founded.

In 1911, the Township Municipality of Guérin was formed from previously unincorporated territory.