Princeton Township was a township in Mercer County, in the U.S. state of New Jersey, that existed from 1838 until the end of 2012. On January 1, 2013, it merged with the Borough of Princeton to form Princeton, New Jersey; both Princeton Township and the Borough of Princeton were dissolved in the merger.

The Borough of Princeton was a borough of New Jersey that existed from 1813 until the end of 2012. On January 1, 2013, it merged with Princeton Township to form Princeton, New Jersey; both the Borough of Princeton and Princeton Township were dissolved in the merger.