The King's Highway Historic District covers the portions of US 206 and Route 27 in New Jersey that connect Lawrenceville (in Lawrence) with Kingston (in Franklin Township / South Brunswick, New Jersey) through Princeton.

This historic roadway dates to colonial times and was a portion of the King's Highway that was laid out by order of Charles II of England to connect Boston with Charleston.

It is lined with many institutions and sites that have played an important role in the History of the United States, including Princeton University and the Princeton Theological Seminary.

The governor's mansion of New Jersey, Drumthwacket, independently listed on the National Register of Historic Places, is found on the road in the western part of Princeton.

The district was added to the National Register of Historic Places on December 21, 2000 for its significance in commerce, exploration, settlement, military, politics, government and transportation from 1660 to 1950.