Fossil Lake is a neighborhood in Fort Collins, Colorado, United States. It sits north of Fossil Creek Reservoir, just a mile west of Interstate 25; including the adjacent neighborhoods of Homestead and Westchase.
Fossil Lake is bordered by Observatory Village to the north, Interstate 25 to the east, Fossil Creek Reservoir to the south and Homestead to the west. Fossil Creek Reservoir Natural Area is 1.7 miles off to the south of Fossil Lake.
Kechter Road serves as a natural boundary to the north that runs east and west, intersecting with I-25 to the east out of the neighborhood. Muskrat Ditch runs through the northwestern of Fossil Lake, passing along Radiant Park and Zach Elementary School. To the west is bordered by Ziegler Road which runs north and south, concurrent with Kechter Road. Trilby Road becomes Lady Moon Drive inside the neighborhood and snakes toward the north and exits on Twin Silo Park.
Green spaces in Fossil Lake include Radiant Park on Kechter Road and Lady Moon Park on Lady Moon Drive.