Horgan-Wallace's mother was Sophia Horgan, a fashion designer, and her father is Steve Wallace, a car dealer. They separated when she was three years old. She was raised as a Jehovah's Witness by her mother in North London and moved schools several times due to clashes with fellow pupils. At the age of 16, Horgan-Wallace stopped living with her mother and stayed with friends before moving to a women's hostel. She was reunited with her father at the age of 18 after he tracked her down.
It has been reported that Horgan-Wallace won a Prince's Trust grant to take a beauty therapy course at college, and that she had jobs in shoe shops and as a promotions girl. Her official biography states that she studied at the London College of Fashion, and that she took part-time promotional jobs to help fund her education.
Horgan-Wallace rose to become notable in the United Kingdom when she was selected as a contestant in the seventh series of the Channel 4 TV series, Big Brother, in 2006. She entered the Big Brother House on Day 12, and became known for her clashes with fellow contestants Nikki Grahame and Grace Adams-Short, and for being voted into the "House Next Door" by the public — a secret house, where she was forced to choose who, out of five new contestants, would become new housemates. Horgan-Wallace reached the final on Day 93; she came third with 22% of the public vote. She was the highest placed female housemate of the series. It was reported that Horgan-Wallace's popularity shocked the show's producers, with tabloid sources suggesting that they had attempted to "engineer" the series' finalists, and did not expect the swing in public support for her.
In August 2010, she turned down an offer to appear in Ultimate Big Brother in order to shoot her scenes as 'Maria' in the British urban comedy movie, Anuvahood instead.
Aisleyne Horgan-Wallace at a red carpet event
Since 2007, Horgan-Wallace has been a frequent guest on the Big Brother support shows, Big Brother's Big Mouth, Big Brother's Little Brother, and latterly, since the show's move to Channel 5 in 2011, Big Brother's Bit On The Side.
2007-present: Transitions into television work
Since 2007, she has appeared in a number of episodes of Charlie Brooker's Screenwipe. She has also presented for shows such as T4. She appeared in BBC One's Test The Nation, on a team with several other Big Brother contestants. She also made a small appearance on The Charlotte Church Show. She appeared in several episodes of the Red TV series Celebrity: Stars at Work, which aired in December 2007 and January 2008. Following on from this, Horgan-Wallace signed a one series contract with Red TV to film a self-titled, fly-on-the-wall documentary Aisleyne. Four episodes were broadcast, the first being aired on 5 March 2008.
In June 2008, Horgan-Wallace made a guest appearance on a special edition of The Friday Night Project, which aired after the launch of Big Brother's ninth series. Her contributions to the show included a sketch which mocked her rivalry with former housemate Nikki Grahame. In August 2008, she made a brief cameo appearance in The Kevin Bishop Show. In October 2008 Aisleyne appeared in Channel 4 and E4's horror Dead Set, which was written by Charlie Brooker. She played herself in this show. She featured in two episodes - episode 1.01 and episode 1.05. In episode 1.05 she played a zombie version of herself.
On 2 March 2009 Aisleyne underwent a make-under for the BBC Three programme Snog Marry Avoid?, presented by Jenny Frost. She was persuaded that a more natural look suited her. In May 2009 she was interviewed for the E4/CH4 programme - Big Brother: A Decade in the Headlines, written and presented by Grace Dent.
In March 2010 she appeared as a guest diner on the Living TV programme, Celebrity Restaurant in Our Living Room. On 5 May 2011 she starred in an episode of Celebrity Hens and Stags for Wedding TV. She helped organize a stag night in Edinburgh including racing in an off-road buggy. In June 2011 she appeared as a contestant in the TV3 (Ireland) series, Celebrity Salon. She finished runner-up behind TV presenter, Alan Hughes.
In January 2012 she appeared in the third series of the Channel 4 show Celebrity Coach Trip, alongside fellow Big Brother alumna Nikki Grahame. The pair were given a red card on Day 3 of the series after clashes with older celebrities including Edwina Currie and Jean Broke-Smith. From December 2012, Horgan-Wallace became a regular guest on the Loaded TV chat show, Looser Women Live, a programme regularly hosted by her friend, the model and fellow reality TV star, Nicola McLean.
On 11 February 2015 she appeared as a claimant on the ITV daytime show Judge Rinder, in a case of unpaid debt against her fellow former BB7 contestant Michael Cheshire, winning her case.
In June 2015, after plans were revealed regarding former "legendary" housemates returning to the Big Brother 16 House as part of "Time Warp" week, Horgan-Wallace was amongst many who were hotly tipped to re-enter. On Day 32, fellow BB7 contestant Nikki Grahame re-entered alongside Brian Belo and Helen Wood. It was later revealed that Horgan-Wallace was meant to enter the House on Day 39, however the plans were scrapped for unknown reasons.
On Day 44, during that week's shopping task, Horgan-Wallace made her return to the House as the fourth "Time Warp" housemate. She later left the House on Day 53.
On 22 September 2015 Horgan-Wallace appeared as a panelist on the Bit on the Side after-show and got into a heated argument with fellow panelist, Farrah Abraham. It's been reported that Horgan-Wallace threw her drink towards Abraham who then began throwing glasses at her. Another panelist, actress, Vicki Michelle was reported to have been sent to the hospital after a glass smashed on her head. Abraham was escorted out by the security team, and later complained of suffering bruising from a chair thrown by fellow guest Janice Dickinson. The event resulted in the local police beginning an investigation into the matter. They issued Abraham and Dickinson with cautions for assault. On 25 January 2016 it was reported that Horgan-Wallace had refused to accept a caution for her part in the incident, and was now facing a court appearance in March 2016, charged with common assault and criminal damage.  However, on 29 January 2016 the CPS reportedly dropped all charges.
After Big Brother, Aisleyne made numerous personal appearances in nightclubs around the UK. She hosted a show for the online radio station, Invincible, was a guest commentator on BBC's Asian Network and made several guest appearances on Choice FM's 'Morning Vybe' show.
She worked as an agony aunt for More magazine and wrote a weekly column for Reveal magazine covering Big Brother 8 as well as a daily blog on their website. She reprised this role for the programme's ninth and tenth series.
In September 2007, it was announced that she had taken control of her own career via her management company, Aisleyne Ltd, along with co-director Richard Skeels.
On 10 February 2008 Aisleyne released a fashion range named "Unique by Aisleyne". She worked with the "high-end" fashion distributors Unique Collections Ltd, to design and produce the outfits. A complementary swimwear range was launched a few weeks later.
It was announced on 24 April 2008, that Mainstream Publishing had bought the right to publish her autobiography, entitled Aisleyne: Surviving Guns, Gangs and Glamour. This book was published on 7 May 2009. The launch party held on 6 May was attended by various celebrities, including Jodie Marsh, Charlie Brooker and Nate James.
Prior to her appearance on Big Brother, Horgan-Wallace had worked as a glamour model. Since the series ended, she has done photo shoots with Nuts, Zoo and the Daily Star. In 2007 she released her own calendar.
Horgan-Wallace is a patron of Brain Tumour UK and acted as an ambassador for Club4Climate, an initiative based around parties in London's West End and elsewhere that aimed to prevent climate change. In 2007, she completed the London 10 kilometre run to raise money for Brain Tumour UK, and she completed the same event on 6 July 2008.
She has been involved with the NHS Stop Smoking campaign in association with Cancer Research UK, and has given her support to No Smoking Day each year since 2008. She also became involved in the "Put the Knives and Guns Down!" campaign encouraging teenagers to get off the streets and stop shootings and stabbings.