Cotter, Brigid Mary (1921–78), chemist and barrister, was born 3 January 1921 in Roscommon, the eldest daughter in the family of twelve children of Nicholas Patrick Cotter, the chief agricultural officer for Roscommon, and his wife, Bridie, née O'Brien. Brigid was educated at the Convent of Mercy, Roscommon, and in the Ursuline Convent, Sligo. In 1944 she graduated B.Sc. in chemistry and mathematics at UCD, and M.Sc. (1945) for her work on epanorin, a chemical constituent of the lichen Lecanora epanora. She was demonstrator in chemistry at UCD from 1945 to 1946, and worked for the Medical Research Council on atmospheric pollution in Dublin. Later she obtained diplomas in bacteriology and food technology. In the period 1947–8 she worked at the Imperial Chemical Industries laboratories in Manchester on moulds and fungi, including penicillin. She taught for a year in Coláiste Ide, Dingle, Co. Kerry, was then employed as chemist in the state laboratory, Dublin (1948–58), and was for four years in charge of the bacteriological section. In 1958 she became an agricultural inspector and was appointed chief technical officer in charge of the butter testing station of the Department of Agriculture, which post she held until her death. She was a fellow of the Institute of Chemists of Ireland.
Cotter embarked on a course of extra-mural law studies at London University, and was awarded the degrees of LLB (in 1963) and LLM (in 1969), subsequently being called to the English and later to the Irish bar (in 1972). She was active on law committees and shortly before her death travelled to Sydney to attend meetings of the International Bar Council. Three Bridget Cotter prizes, founded on gifts from Cotter, are awarded to external law students of the University of London. She was a member of the RDS and was a keen bee-keeper. She died unmarried in Dublin on 20 November 1978.