Boysen State Park is a public recreation area surrounding the Boysen Reservoir, an impoundment of the north-flowing Wind River, in Fremont County, Wyoming.

The state park covers more than 35,000 acres (14,000 ha) at the south end of the Owl Creek Mountains at the mouth of the Wind River Canyon.

It is named for Asmus Boysen, who built the site's first dam in 1908.

[4] The park offers multiple campgrounds, boat launches, and a privately operated marina.

Game fish found in the reservoir include walleye, sauger, perch, crappie, ling, rainbow, cutthroat, and brown trout.