Wyoming Highway 77 is a state highway in northesatern Carbon County, Wyoming that runs from its south end at WYO 487 to a north end at WYO 487.

Wyoming Highway 77 begins at Wyoming Highway 487, 22 miles (35 km) north of Medicine Bow to WYO 487 near the Shirley Basin Rest Area, which is located 27 miles (43 km) south of the WYO 220-WYO 487 junction. State Route 77 stays to the west of WYO 487 and Shirley Basin, and also acts as an alternative route to WYO 487 between the two points.

Wyoming Highway 77 was formerly numbered as WYO 487 while present day Highway 487 was designated as WYO 75. WYO 75 was created during the early 1970s with the creation of the Wyoming secondary state route system. When Wyoming Highway 487 was rerouted over Highway 75 in the mid-1970s, old WYO 487 was redesignated as WYO 77.