She was one of the last two debutantes to be presented to the Queen at Buckingham Palace in 1958; the final such ceremony.
She made many guest appearances in several popular shows of the 1960s and 1970s, including The Saint, Department S, Jason King, Randall and Hopkirk (Deceased), The Persuaders! and The Sweeney.
In the same year Lloyd played the regular role of secret agent Cordelia Winfield, alongside Steve Forrest in the 1965–66 British ITC television series The Baron. Originally Lloyd's character only appeared in the pilot episode, with Steve Forrest's sidekick played by Paul Ferris. Pressure from the American television network who were to screen the show replaced Ferris with Lloyd.
In 1971, Lloyd starred in a stage version of the TV series The Avengers playing John Steed's sidekick, Mrs Hannah Wild. She also appeared with several other stars in the 1976 Lindsay Shonteff imitation James Bond film No. 1 of the Secret Service.
In Crossroads Lloyd played the wife of actor Ronald Allen, who was sacked on the same day she was. They were good friends, having met shortly after his long-term life partner, fellow Crossroads actor Brian Hankins, had died from cancer in 1978. Lloyd's friends were surprised when, in 1991, she married an ailing Allen six weeks before his own death, on 18 June, from cancer.
Lloyd joined the long-running British soap opera Crossroads in 1979. She played Barbara Hunter (née Brady) until she and her on and also off screen partner Ronald Allen were dropped from the series in 1985.
Her other film credits include Corruption, Revenge of the Pink Panther, The Stud and The Bitch. On her Twitter page Joan Collins said that she and Lloyd had to get drunk prior to their nude scenes. She reunited with Michael Caine in Bullet to Beijing (1995), one of the later Harry Palmer films.
Sue Lloyd died on 20 October 2011, aged 72, from cancer.
