Sheila Christina Tinney (née Power, 15 January 1918–27 March 2010) was an Irish mathematical physicist. Her 1941 PhD from the University of Edinburgh, completed under the supervision of Max Born in just two years, is believed to make her the first Irish-born and -raised woman to receive a doctorate in the mathematical sciences.
Sheila Christina Power was the fourth of six children born in Galway city to Michael Power (aka Mícheál de Paor, originally from rural Kilkenny, Chair of Mathematics at University College Galway from 1912–1955) and Christina Cunniffe (who died in childbirth when Sheila was 12). She was educated by the Dominican nuns, both in Galway and in Dublin, and was awarded Honours in Mathematics in the Leaving Certificate Examination (the nation's secondary school exit exam), one of only 8 girls to do so in the whole country. After one year attending UCG, she switched to University College Dublin, from which she graduated with a BSc in 1938, with First Class Honours in Mathematics, and ranked at the top of her class. She did her Master's at UCD in 1939, and was subsequently awarded a National University of Ireland travelling studentship, which enabled her to undertake research at the University of Edinburgh in Scotland. Two years later, in 1941, she earned her doctorate under the supervision of the celebrated physicist Max Born on the stability of crystal lattices.
Returning to Dublin, she became an assistant lecturer at University College Dublin, and was also one of the first three scholars appointed to the brand new Dublin Institute for Advanced Studies (DIAS), in October 1941. While at the DIAS she worked with Paul Dirac, Arthur Eddington and Erwin Schrödinger. She developed a great interest in quantum physics, and wrote papers with Schrödinger, Hideki Yukawa, and Walter Heitler. From September of 1948 to June of 1949 she took a leave of absence from UCD and was a visiting scholar at the Institute for Advanced Study in Princeton where worked in an environment that included Freeman Dyson, Hermann Weyl, Harish-Chandra, and Albert Einstein.