Sue Osman is a fictional character from the BBC soap opera EastEnders, played by Sandy Ratcliff. She is one of the serial's original characters, appearing in its first episode on 19 February 1985 and departing on-screen in May 1989. Created by Tony Holland and Julia Smith, Sue is portrayed as argumentative, insecure and tragic. A pivotal storyline in the character's narrative is the cot-death of her son, which was one of the show's first controversial plots. During her four years on-screen, the character contends with a phantom pregnancy, marital breakdown and finally insanity. Ratcliff left the role in 1989.

EastEnders is a British television soap opera created by Julia Smith and Tony Holland which has been broadcast on BBC One since February 1985. Set in the fictional borough of Walford in the East End of London, the programme follows the stories of local residents and their families as they go about their daily lives. Within eight months of the show's original launch, it had reached the number one spot in BARB's television ratings, and has consistently remained among the top-rated series in Britain. Four EastEnders episodes are listed in the all-time top 10 most-watched programmes in the UK, including the number one spot, when over 30 million watched the 1986 Christmas Day episode. EastEnders has been important in the history of British television drama, tackling many subjects that are considered to be controversial or taboo in British culture, and portraying a social life previously unseen on UK mainstream television.