Joyce was born in Portsmouth in 1920 and, in her youth, first joined Portsmouth’s Labour League of Youth and then the Young Communist League. She joined the Communist Party in 1939.
She successfully took the examinations to join the Civil Service and became the Personal Assistant to Lord Wooton, the Food Minister, during war years. During this period, she was a member of Highgate (WaterlooPark) Communist Party branch and lived in the house of the famous Communist conductor Geoffrey Corbett (see separate entry).
Her stint in the civil service would have been cut short by the 1948 ban on civil servants being members of the Communist Party.
In February 1950, she was part of a delegation of women for peace to lobby the American Embassy.
Joyce Miller moved to Hayes, West Middlesex, in 1958 with her son and daughter. There, she became active in CND and on the Aldermaston marches. Miller lived in Moray Avenue, Hayes, when she stood as a Communist candidate in the local elections of 1960.