Pennsylvania Route 27 is a 65.7-mile-long (105.7 km) state highway that is located in northwest Pennsylvania in the United States.

U.S. Route 6 (US 6) travels east–west near the north edge of the U.S. state of Pennsylvania from the Ohio state line near Pymatuning Reservoir east to the Mid-Delaware Bridge over the Delaware River into Port Jervis, New York. It is the longest highway segment in the commonwealth. Most of it is a two-lane rural highway, with some freeway bypasses around larger towns. Except east of Dunmore, where it is paralleled by Interstate 84 (I-84), it is the main route in its corridor. What is now I-80—the Keystone Shortway—was once planned along the US 6 corridor as a western extension of I-84. The corridor was originally the Roosevelt Highway from Erie, Pennsylvania, to Port Jervis, New York, designated Pennsylvania Route 7 (PA 7) in 1924. The PA 7 designation soon disappeared, but, as US 6 was extended and relocated, the Roosevelt Highway followed it. The Pennsylvania section of US 6 was renamed the Grand Army of the Republic Highway in 1946; this name was applied to its full transcontinental length by 1953.