Susan McKenna-Lawlor is an Irish astrophysicist. She is professor of experimental physics at Maynooth University.

McKenna-Lawlor was the principle investigator for an experiment on the European Space Agency (ESA) Giotto mission. In 1986 she founded the space instrumentation company Space Technology Ireland Ltd (STIL) with venture capitalist Dermot Desmond. STIL manufactures instruments for space missions and McKenna-Lawlor is the managing director.

McKenna-Lawlor led an international team of scientists in building a particle detector capable of detecting energies between 30 kiloelectronvolts and several megaelectronvolts for the Soviet Union's Phobos spacecraft in 1988. The success of the detector led Soviet scientists to ask her to contribute a similar device for their 1994 Mars mission.

She developed instruments to monitor the solar wind on Mars for the ESA Mars Express mission.

STIL designed the onboard Electrical Support System processor unit for the Rosetta spacecraft. McKenna-Lawlor also represented Ireland on the Steering Board of the Rosetta's Philae lander that touched down on comet 67P/Churyumov–Gerasimenko.

McKenna-Lawlor wrote the 1998 book Whatever Shines Should be Observed. She was a member of the National University of Ireland Senate and of Maynooth University's Governing Authority.