Pennsylvania Route 177 (PA 177) is an 9-mile (14 km) long state highway located in York county in Pennsylvania. The southern terminus is an intersection with PA 74 and Township Route 4026 (Old York Road) in Rossville. From this intersection, PA 177 bisects the southwestern portion of Pinchot Lake and continues along the northwestern side of Gifford Pinchot State Park. Just south of Lewisberry, PA 177 intersects PA 382 and marks the northern terminus of PA 392 to the north of town. The northern terminus is at PA 262 between Yocumtown and Frogtown, just after an interchange with I-83.

PA 177 begins at an intersection with PA 74 in the community of Rossville in Warrington Township, heading northeast on two-lane undivided Rosstown Road.The road passes through wooded areas with some homes before entering forested areas of Gifford Pinchot State Park and crossing a portion of Pinchot Lake. The route continues to form the northwestern boundary of the state park, passing a few homes and fields. Upon reaching Maytown, PA 177 leaves the state park and turns north through more hilly forests. The road crosses the Stony Run and becomes the border between Fairview Township to the west and Newberry Township to the east, passing through a mix of farms and woods with a few homes. Upon crossing PA 382, the route enters Lewisberry and becomes Market Street as it is lined with homes. After leaving Lewisberry, PA 177 continues northeast into Newberry Township and becomes Potts Hill Road as it passes through farmland with some residences. The road ascends a forested hill as it becomes the border between Fairview Township and Newberry Township again.

Upon intersecting PA 392, Potts Hill Road turns east to follow that route and PA 177 continues north on Wyndamere Road. The route descends the hill into a mix of farms and homes, with the road fully entering Fairview Township. The road passes a mix of homes and businesses as it comes to an interchange with I-83. Past here, the PA 177 passes more residences before turning northwest onto Old York Road and ending at PA 262 a short distance later.

The entire route is in York County.