Olla is a town in northwest La Salle Parish, Louisiana, United States, located in the heart of the Louisiana Central Hill Country. Olla has a federally recognized downtown Historic District and a Louisiana historic marker. The population was 1,385 at the 2010 census. Olla Historic District is the site of the annual Central Louisiana Bluegrass Festival each April and to the Olla Homecoming Parade, Celebration, and Festival that coincides with LaSalle High School Homecoming each autumn.