Pennsylvania Route 690 (designated by the Pennsylvania Department of Transportation as SR 690) is an 12.58-mile (20.25 km) long state highway located in Lackawanna and Wayne counties in Pennsylvania. The western terminus is at Route 502 in Spring Brook Township. The eastern terminus is at Route 590 in Salem Township.

Route 690 begins at an intersection with Route 502 in the Spring Brook hamlet section of Spring Brook Township just north of the Watres Reservoir. Route 690 heads northward from Route 502, passing some local residents and nearby Benjamin Pond before beginning to wind through the woodlands north of the hamlet. After the intersection with Thomas Road, the highway progresses eastward for a short distance, turning northeastward into a small resident segment near Maple Lake. After intersecting with Maple Lake Road, Route 690 turns eastward into the hamlet of Maple Lake. The hamlet is residential, as the road becomes the main street, intersecting with Route 307. There, Route 690 turns northward out of Maple Lake, winding into Exit 22 of Interstate 380 (a southbound only exit). After Interstate 380, Route 690 makes a short curve to the northeast before entering Moscow, where it gains the name of Church Street.

Heading through Moscow, Route 690 is primarily residential, passing the local high school and into downtown, where commercial businesses begin to appear. In downtown Moscow, the highway intersects with Route 435 (Main Street) and turns south onto a concurrency on South Main Street. Paralleling the tracks of the former Delaware, Lackawanna and Western Railroad, Route 690 soon splits off under the tracks. Turning northward after the underpass, Route 690 heads northward on Market Street, passing the former Moscow train station. The stretch along Market Street is mainly commercial, before the designation turns off Market at the intersection with Brook Street. Along Brook Street, the route is primarily residential. Before crossing the borough line, Route 690 remains known as Brook Street, but after the borough line, the route becomes woodlands. Soon changing names to Madisonville Road, Route 690 passes a residential complex and enters Madisonville, a rural hamlet. After the intersection with Reservoir Road, the highway turns from the northeast and curves into the hamlet of Aberdeen.

After crossing through Aberdeen, Route 690 turns northeastward into the hamlet of Quicktown, where the highway crosses under Interstate 84, but does not intersect with it. Just after crossing under Interstate 84, the route crosses the county line into Wayne County and gains the name Hollisterville Road. From there, Route 690 heads northeast away from Interstate 84 in rural settings until entering the hamlet of Hollisterville. There, the route passes several residences before intersecting with Route 590 (Hamlin Highway). The right-of-way merges into Route 590 and the designation of Route 690 ends.