The Doctor of Philosophy (PhD) in Aerospace Engineering is the highest academic qualification available in the field, representing mastery of advanced theory and original research. Unlike undergraduate or master's programs that emphasise coursework and applied training, a PhD focuses on independent research and the development of new knowledge through a dissertation, making a significant and original contribution to the discipline. Candidates undertake a minimum of three to four years of full-time supervised research, culminating in the submission of a doctoral thesis that demonstrates their capacity to advance scientific and engineering understanding in areas such as aerodynamics, propulsion systems, spacecraft design, fluid mechanics, structural analysis, robotics and autonomy, and computational methods.

This qualification is designed for engineers and scientists who wish to work at the frontier of aerospace knowledge — whether as academic researchers, senior industry specialists, or innovation leaders. Research areas in Australian programs commonly include computational fluid dynamics (CFD), hypersonic flight, unmanned aerial vehicles (UAVs), satellite systems, advanced materials and composites, space systems engineering, aircraft control, and autonomous aerospace technologies. Employers of PhD graduates span government defence agencies, national research organisations such as the CSIRO and DST Group, leading aerospace companies including Boeing Defence Australia, Airbus, Lockheed Martin, and Raytheon, as well as universities, the Australian Space Agency, and a growing number of Australian space and defence start-ups.

Australian PhD programs in Aerospace Engineering typically require applicants to hold a bachelor's degree with at least Second Class Honours (Upper Division) — commonly First Class Honours — in a relevant engineering or science discipline, or a master's degree with a substantial research or thesis component. Some programs also consider a combination of qualifications, research publications, and relevant professional experience as equivalent to these academic criteria. Applicants must also identify and secure a willing supervisory academic whose research interests align with their proposed study area, and in most cases submit a detailed research proposal outlining their intended study, demonstrating originality and alignment with faculty expertise.

For international applicants, English language proficiency is mandatory. The standard requirement is an IELTS overall band score of 6.5 (with no individual band below 6.0), or a TOEFL score of 79–90, though specific requirements vary by institution. Domestic students who are Australian citizens or permanent residents may be eligible for a Commonwealth-funded Research Training Program (RTP) place, which can provide full tuition fee exemption and a living allowance stipend, making the PhD financially accessible. Applicants with qualifications below the standard threshold may still be considered if they can demonstrate first authorship on a refereed journal publication or have appropriate research experience. A bachelor's degree requiring at least four years of full-time study in a relevant discipline is also commonly accepted as a pathway to PhD candidacy.