Francis Dominic Murnaghan (August 4, 1893 – March 24, 1976) was an Irish mathematician, former head of the mathematics department at Johns Hopkins University. His name is attached to developments in group theory and mathematics applied to continuum mechanics (Murnaghan and Birch–Murnaghan equations of state).
Frank Murnaghan was born in Omagh, Co. Tyrone, Ireland, seventh of the nine children of George Murnaghan, Nationalist MP representing Mid Tyronne constituency. He graduated from Irish Christian Brothers secondary school in 1910, and University College Dublin with first-class honors BSc in Mathematical Sciences in 1913. Following an MSc in 1914, he was awarded an NUI Travelling Studentship, which funded him to pursue his doctorate at Johns Hopkins University. In 1916, after just two years working under department chair Frank Morley's new PhD student Harry Bateman, he was awarded the Ph.D.
He then lectured at Rice University, and returned to Johns Hopkins in the rank of Associate Professor at the young age of 25. In 1928 he was promoted to Professor and became only the fourth head of the Department of Mathematics (after J.J. Sylvester, Simon Newcomb and Frank Morley). After his retirement in 1949, he worked at the Instituto Tecnológico de Aeronáutica near São Paulo, Brasil, but returned to Baltimore in 1959. He continued working as a consultant for the Marine Engineering Laboratory; his last publication appeared in 1972.