Darcey was born in London and attended the Arts Educational School, studying all forms of stage art. Aged 13, she moved to White Lodge (The Royal Ballet Lower School) to concentrate on ballet and graduated into the Upper School in 1985, staying for two years and appearing in the 1986 and 1987 School performances at Covent Garden. She then joined Sadler's Wells Royal Ballet (now The Birmingham Royal Ballet) for the 1987/88 season.
The late Kenneth MacMillan had noticed Darcey’s exceptional technique while she was still a student, and cast her in the principal role of his ballet Concerto for the 1986 School performance. During her first season with Sadler’s Wells Royal Ballet he chose her for the leading role in The Prince of the pagodas, his new work for The Royal Ballet. She joined the Royal Ballet as a Soloist, becoming a First Soloist in September 1989. Just three months later, on the first night of The Prince of the pagodas, Darcey was promoted to the rank of Principal. She was just twenty at the time.
She created two major roles for MacMillan before his death: Princess Rose in The Prince of the pagodas and Masha in Winter dreams, which was premiered in February 1991. The final Farewell pas de deux of Winter dreams had been created in advance of the full ballet and was performed at the Queen Mother’s 90th Birthday Tribute at the London Palladium in July 1990. Her other roles in MacMillan’s ballets include the title roles in Manon and Romeo and Juliet, the leading roles in Song of the Earth and Elite syncopations, the Agnus Dei role in Requiem, Mitzi Casper in Mayerling and Mathilde Kschessinska in Anastasia.
Her classical repertory includes Odette/Odile in Swan lake, Princess Aurora in The Sleeping beauty, the Sugar Plum Fairy in The Nutcracker, Nikiya and Gamzatto in La Bayadère, and the title roles in Giselle and Raymonda (Act III).
In the Royal Ballet’s Balanchine repertory, she appeared in the first performances by the Company of Rubies and Stravinsky's Violin Concerto (Aria I) and also danced the central roles in Agon, Symphony in C (Second Movement), Tchaikovsky pas de deux, Apollo (Terpsichore), Prodigal son (Siren), Duo concertant, Ballet imperial and Serenade (pas de deux girl).
She has danced the title role in Frederick Ashton’s Cinderella, Monotones II, Sacred Love in Les Illuminations and the pas de deux and Bariosova Variation in Birthday offering; leading roles in William Forsythe’s In The middle, somewhat elevated and Herman Scherman (pas de deux); the Prostitute in the first Royal Ballet performance of Glen Tetley’s La Ronde; the Black Queen in Ninette de Valois’ Checkmate; Ashley Pages’ pas de deux … now languorous, now wild … and the company premiere of Twyla Tharp’s Push comes to shove.
She has also performed leading roles in Twyla Tharp’s first work for The Royal Ballet, Mr Worldly Wise (Mistress Truth-on-Toe), Matthew Hart’s Dances With death, Christopher Wheeldon’s pas de deux Pavane pour une infante défunte, Glen Tetley’s Sextet amores and Mark Baldwin’s Towards poetry.
Darcey's televised performances include The Prince and the pagodas and the Queen Mother’s 90th Birthday Tribute in 1990, La Bayadère (with Darcey in the role of Gamzatti) followed in 1991 and Winter dreams in 1992; she danced the Tchaikovsky pas de deux in the Winter Gala televised in 1997, where she also appeared as the Lilac Fairy in the final Sleeping Beauty tableau, symbolizing the closure of the Royal Opera House for redevelopment. A South Bank Show documentary on Darcey and her fellow principal Viviana Durante was broadcast in October 1992, and she has been seen in numerous televised galas. She most recently appeared on television in a Carmen dance specially choreographed by William Tuckett for the Lesley Garrett Show.
Darcey's international performances include the Gala des Étoiles held in Paris in October 1991 and featuring leading dancers from all over the world. In June 1993 she danced the Agon pas de deux at the Balanchine Gala in New York, returning to dance with the New York City Ballet in February 1994 in Agon and Symphony in C, and in the Summer of 1995 to appear in Balanchine’s productions of Swan lake (Act II) and A Midsummer night’s dream. She has also been a guest internationally working with several other companies. In February 1998 she danced with the Kirov at St. Petersburg performing the role of Nikiya in La Bayadère.
She was voted Dancer of the Year in December 1990 by the readers of Dance & Dancers magazine. In February 1991 she was presented with the Variety Club of Great Britain’s Sir James Garreras Award for the most promising newcomer of 1990, and one week later with the Evening Standard Ballet Award for 1990. In April 1991 she was selected as the joint winner of the Cosmopolitan Achievement Award in the Performing Arts category.
A portrait of her by the artist Allen Jones RA was commissioned by the National Portrait Gallery and unveiled on 23 May 1994. She was nominated an Officer of the Order of the British Empire (OBE) in the 1995 New Year's Honours List.