Lolo is a census-designated place (CDP) in Missoula County, Montana, United States. It is part of the Missoula Metropolitan Statistical Area. The population was 4,399 at the 2020 census, an increase from its population of 3,892 in 2010. It is home to Travelers' Rest State Park, a site where Lewis and Clark camped in 1805 and again in 1806.

Missoula County is located in the State of Montana. As of the 2020 census, the population was 117,922, making it Montana's third most populous county. Its county seat and most populous city is Missoula. The county was founded in 1860.