Little Lehigh Creek is approximately 24.0 miles (38.6 km) long and is located in the Lehigh Valley region of eastern Pennsylvania. It is sometimes referred to as the Little Lehigh River. It is the largest tributary of the Lehigh River.
The creek flows in a winding course through the Lehigh Valley. It originates in Longswamp Township in Berks County and flows generally northeast through Lower Macungie Township and Salisbury Township. In the city of Allentown, it receives Jordan Creek, just before flowing into the Lehigh River.
The Little Lehigh has 88.8 square miles (230.0 km2) of drainage area in Lehigh County and 18.7 square miles (48.4 km2) of drainage area in Berks County.