A novel inbred maize line designated PHADA and seed, plants and plant parts thereof. Methods for producing a maize plant that comprise crossing inbred maize line PHADA with another maize plant. Methods for producing a maize plant containing in its genetic material one or more traits introgressed into PHADA 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 inbred line PHADA or a trait conversion of PHADA with another maize line. Inbred maize lines derived from inbred maize line PHADA, methods for producing other inbred maize lines derived from inbred maize line PHADA and the inbred maize lines and their parts derived by the use of those methods.