HP3

HP3 or variant, may refer to:


 * HP3, a postcode for Hemel Hempstead, see HP postcode area
 * hP3, a Pearson symbol
 * Harry Potter and the Prisoner of Azkaban, the third Harry Potter novel
 * Harry Potter and the Prisoner of Azkaban (film), the third Harry Potter film
 * Handley Page Type C aka H.P.3, an airplane
 * HP-3, a glider designed by Richard Schreder
 * HP3, a type of photographic stock, see Ilford HP
 * HP3, Heat Flow and Physical Properties Package, an instrument aboard the InSight Mars lander