This is a list of properties and districts listed on the National Register of Historic Places in Pennsylvania. As of 2015[update], there are over 3,000 listed sites in Pennsylvania. Sixty-six of the 67 counties in Pennsylvania have listings on the National Register; Cameron County is the only county without any sites listed.
The following are approximate tallies of current listings in Pennsylvania on the National Register of Historic Places. These counts are based on entries in the National Register Information Database as of April 24, 2008 and new weekly listings posted since then on the National Register of Historic Places web site. There are frequent additions to the listings and occasional delistings and the counts here are not official. Also, the counts in this table exclude boundary increase and decrease listings which modify the area covered by an existing property or district and which carry a separate National Register reference number. 16 percent of the NRHP's in Pennsylvania are in Philadelphia, and nearly 40 percent are located within the Delaware Valley.