Titmuss was born on 8 February, 1976. She grew up in Ruskington, where her parents were teachers, and took her A levels at Kesteven and Sleaford High School. Her parents divorced when she was 17, and her father moved to Argyll, Scotland, where he re-married. She graduated from City University in St Bartholomew's Hospital in 1998, and became a staff nurse at London's University College Hospital. She also worked at the Royal Brompton Hospital, and while here she was harassed by a senior house officer, Dr. Shibley Rahman, in 2004. After these incidents (which included confronting Titmuss while she showered), Dr. Rahman was evenually found guilty of misconduct by a General Medical Council tribunal.

Titmuss met TV presenter John Leslie at a party in 1998. The pair quickly formed a relationship, and Titmuss lived between her student nurse accommodation at the hospital and Leslie's home in Barnes, south-west London.

In 2002 presenter Ulrika Jonsson released her autobiography, in which she suggested that she had been raped earlier in her career by a now well-known TV presenter. Weeks later, the News of the World ran front page pictures of John Leslie snorting cocaine in a cafe. The following week, pictures appeared in the paper of Leslie, Titmuss and other women taking part in sex-sessions at Leslie's home, including Lanre Onabowale, posing as basketball player Jayson Blayde, and his girlfriend.

She played the clarinet at school and likes classical music.

As of June 2007, Abi now unveils the opening of new stores for Virgin Media. She attended the unveiling of the Basingstoke branch in Festival Place on 16th June, 2007.

The following week on Matthew Wright's live Five morning television show, Leslie was named as the anonymous celebrity linked to the rape accusation in Jonsson's autobiography.

Leslie was arrested by the Metropolitan Police Force, and faced a court trial, throughout which Titmuss was demurely present at his side. The image of Titmuss at this time was in complete contrast to that which had been portrayed in the various newspaper articles and pictures leading up to the trial, and she received high praise in most editorials.

When Leslie was found not guilty, the assumption was that the couple would continue their relationship. However, Leslie's career had stalled, whereas Titmuss had raised her image to the point where she was offered various television presenting jobs. Her tabloid-friendly looks and ease in front of the camera gained her a part-time post as a reporter for Leslie's friends Richard and Judy, undertaking occasional projects while continuing her job as a nurse.

Unfortunately, she lost this job a few months later, when a ménage à trois home sex video of Leslie, Titmuss and another woman found its way onto the Internet. Leslie and Titmuss immediately separated, and Titmuss insisted that Leslie had released the tape to the press in light of his extreme need to fund his lifestyle.

Titmuss fully engaged her new image, and undertook a series of interviews promoting her image as a real sex star and Britain's #1 pinup. In her own words to the Sunday Mirror she stated: "I'm not like those glamour girls who say: 'I'm really dirty, I'm really bad', then just pose around. I really am dirty and bad - I love sex."

She took up presenting on pornographic channel Television X, released a risqué fitness video, authored an erotic novel published by Black Lace, made personal appearances in nightclubs all over the UK and Ireland, made millions by licensing every image of herself published to her own trademark, and wrote a regular sex advice column for FHM. On numerous occasions, Titmuss has modelled for many UK men's magazines, such as FHM (whose readers voted her #7 in FHM 100 Sexiest Women in the World 2005), Nuts, Zoo Weekly, Loaded, GQ and Maxim magazines, others such as The Sunday Times Style and tabloid newspapers including The Sun, The News Of The World, The Daily Mirror, The People and The Daily Star.

According to her official website, Titmuss appeared on 38 magazine covers during 2004 and 2005. In December 2004, Titmuss appeared on the front cover of FHM magazine with Victoria Silvstedt.

She used her image and status to join ITV1's Celebrity Love Island. Her other television work includes training as a chef on the 2004 series of Hell's Kitchen, and in 2005, she appeared on Channel 4's The Friday Night Project as a regular guest feature, and in "Abi Titmuss: A Modern Day Morality Tale", a fly-on-the-wall documentary for Channel 4.

In 2005, Titmuss appeared in a high fashion shoot in Pop magazine, which commented on her status as the Face of 21st century celebrity.

After taking a break from modelling work, Titmuss has recently relaunched her glamour career as a brunette with an appearance on the cover of Zoo Weekly magazine and the sale of the official Abi Titmuss Calendar 2007.

She recently appeared as a celebrity on reality series Deadline with Janet Street Porter as an editor on ITV2. The show followed a number of celebrities as they attempted to produce a celebrity-based magazine each week, published as a supplement to Closer magazine. Titmuss was the fourth celebrity to be sacked from the show. She has previously guest-presented shows on Virgin Radio, MTV and LBC radio.

On April 25th, 2007, it was announced that Titmuss had made an appearance for a third year running in FHM's annual 100 Sexiest Women in the World readers' poll, peaking at #80 (#7 in 2005, #95 in 2004).

After taking a short course at the Central School of Speech and Drama, Titmuss made her West End acting debut in March 2006 playing a prostitute with a multiple personality disorder in Two Way Mirror by Arthur Miller, at the Courtyard Theatre in Kings Cross. Despite her self-confessed nervousness, theatre critics actually praised her first foray into the world of acting, citing that she had great potential and was clearly a capable actress.

In 2006, Titmuss filmed a small role in the major motion picture Goal! 2, but her scenes were cut from the final edit of the picture, which was released in 2007.

In a touch of irony, Titmuss was due to have been the subject of a theatre production herself in a musical satire entitled Being Abi, performed by students in her home county of Lincolnshire. Devised by pupils at Boston College in May 2006, it was scheduled for a three-day run before being cancelled by the two of the performers' concerned parents, who objected to some of the production's content.

In February 2007, Titmuss won a Fringe Report Award for Best West End Debut for her role in Two Way Mirror.

She most recently played a version of herself in the second series premiere of Rob Brydon's Annually Retentive, which aired 30 April, 2007 on BBC Three.

Titmuss produced a book co-written with Jayne Lockwood, published on July 7th 2005 called Ten Fantasies (ISBN 9780753510377), by Virgin Books, in which the content is about her ten most secret (sexual) fantasies. She has banned her mother from reading it.

She had her first serious relationship with John Longford, when living in Ruskington. Following her long term and latterly publicly exposed relationship with John Leslie, and her image as a real sex kitten, her personal life is closely followed. She dated comedians David Walliams and Patrick McGuinness post break-up with Leslie, and had a longer term relationship with fellow "Celebrity Love Island" contestant Lee Sharpe. After Sharpe had a series of affairs (including with Big Brother star Lisa Jeynes), the relationship broke up, and Titmuss had a short relationship with dancer Brendan Cole, and was linked to Russell Brand. She now claims presently to be single, although she has recently been seen out on the town with British rock singer Joe Breakdown