 Martin was born in Adelaide and was educated at the Oakbank Area School and the Adelaide High School before studying at the University of Adelaide.Brian Ross Martin was admitted to practise law in 1970, becoming an assistant Crown Prosecutor in Adelaide in 1974 and eventually the Senior Crown Prosecutor in 1982.He was appointed as a Queen's Counsel (QC) in 1984 and in 1991 was appointed Senior Counsel assisting the Royal Commission into WA Inc. Martin was appointed as the Commonwealth Director of Public Prosecutions in 1997 a position he held until taking up his appointment as a Judge of the South Australian Supreme Court.