A novel maize variety designated PHP5D and seed, plants and plant parts thereof. Methods for producing a maize plant that comprise crossing maize variety PHP5D with another maize plant. Methods for producing a maize plant containing in its genetic material one or more traits introgressed into PHP5D through backcross conversion and/or transformation, and to the maize seed, plant and plant part produced thereby. Hybrid maize seed, plant or plant part produced by crossing the variety PHP5D or a trait conversion of PHP5D with another maize variety. Inbred maize varieties derived from maize variety PHP5D, methods for producing other inbred maize varieties derived from maize variety PHP5D and the inbred maize varieties and their parts derived by the use of those methods.