Pennsylvania Route 145 is a 20.89 mi (33.62 km) long north–south state highway in the Lehigh Valley area of eastern Pennsylvania. It connects Interstate 78 (I-78) and PA 309 in Lanark, Lehigh County, north to PA 248 in Lehigh Gap, Northampton County.

Interstate 78 (I-78) is a major east–west Interstate Highway stretching from Union Township, Lebanon County, Pennsylvania, in the west to the Holland Tunnel and New York City in the east. In Pennsylvania, I-78 runs for about 78 miles (126 km) from the western terminus at I-81 in Union Township east to the New Jersey state line near Easton in Northampton County.