Wyoming Highway 77 (WYO 77) is a remote state highway in northeastern Carbon County, Wyoming, United States, that forms a western loop off of Wyoming Highway 487 (WYO 487), and connects with WYO 487 north of Medicine Bow and again south of Casper.
WYO 77 begins at a T intersection with WYO 487, about north of Medicine Bow. From its southern terminus it heads northwesterly for roughly before turning north. After heading northerly for roughly , WYO 77 reaches its northern terminus at another t intersection with WYO 478, approximately west of the Shirley Rim Rest Area and about south of Capser.
The entirety of WYO 77 maintains a speed limit of and is closed during winters.