Port Alexander Seaplane Base (IATA: PTD, ICAO: PAAP, FAA LID: AHP) is a city owned, public use seaplane base located in Port Alexander, a city at the southeastern corner of Baranof Island in the Petersburg Borough of the U.S. state of Alaska. It is included in the National Plan of Integrated Airport Systems for 2011–2015, which categorized it as a general aviation facility.

As per Federal Aviation Administration records, the airport had 139 passenger boardings (enplanements) in calendar year 2008, 189 enplanements in 2009, and 146 in 2010. Scheduled airline passenger service is subsidized by the United States Department of Transportation via the Essential Air Service program.

Although most U.S. airports use the same three-letter location identifier for the FAA and IATA, Port Alexander is assigned AHP by the FAA and PTD by the IATA. The airport's ICAO identifier is PAAP.