King was the face of Boddingtons beer in 2004. She made appearances in a series of recurring television adverts for Daz titled “Cleaner Close”, a parody of soap operas. In the late 1990s, King appeared in various modelling shoots.

In 2006, she became engaged to fellow actor Jim Alexander who co-starred in several series of Dream Team with her, as well as the Daz adverts. However, the pair split in early 2007. She briefly dated fellow soap star Louis Emerick following the split.

The Actress dated Adam Huckett, a Coronation Street sound technician from April 2007. In 2008, it was announced she was expecting her first child. She gave birth to their daughter, Daisy Mae, on 11 February 2009, in a Manchester hospital. The baby weighed 6lbs 7oz. A Coronation Street spokeswoman said "No name has been decided on yet but mum and baby are doing well. Everyone at Coronation Street sends Alison and her partner Adam Huckett their best wishes on the birth of their daughter." King became engaged to Huckett in September 2011 while on a trip to Paris, however, on 16 October 2012 it was reported that the engagement was off as they had split up.

In 2011, King's character was raped by her boyfriend, Frank Foster. This storyline had a massive public impact and saw a high rise in reported rapes across the United Kingdom. King spoke of how there was an 800% increase in calls to support organisations after the storyline had aired, and that people had contacted her about their real-life experiences, some of whom she has kept in communication with. Her performance in the rape storyline led to a Best Actress award at the 2012 British Soap Awards.

In 2014, it was reported that the Actress had requested extra security from ITV bosses after it emerged she had a female stalker. Despite formal requests to stay away after being found lurking outside of her house, the woman approached her at a public event, Southport Flower Show, resulting in a distressed King fleeing the event earlier than intended.

Alison King was born at the Leicester Royal Infirmary. She is the youngest of three daughters and a son born to Alex and June King, who were both Nurses at the hospital. She was raised in the family home first in Ratby Lane, Markfield, Leicestershire where she went to Markfield Mercenfeld Primary School and was taught by Tracey Lee, mother of Sammy Lee, and Gillian Sykes, then in Kirby Muxloe. She attended South Charnwood High School, where she first took an interest in acting. She continued to act while attending Groby Community College, where a Teacher would offer drama and dance classes to students in their free time. Alison was raised as a Christadelphian and attended the Christadelphian Church at Westleigh, Leicester, where she was baptised as a teenager. At the age of 18, King moved to Newquay, Cornwall, where she worked at Fat Willys Surf Shack. She surfed in her spare time, and spent four years as a dental nurse. When she was 22, she enrolled at the North Cheshire Theatre School. While at drama school, she underwent cosmetic surgery at a London dental practice to improve her smile, stating her teeth had been ruined by sucking her thumb as a child, and later had more surgery in 2015. During her time there she got her first television role, playing Helen, a hair salon crimper, in two episodes of Brookside. Before the conclusion of her three-year diploma, she was cast in the major role of Lynda Block in Sky One's Dream Team.

Since 2016, King has been dating Hollyoaks assistant Director Paul Slavin. The relationship was revealed after they were photographed by the press and there was speculation as to his identity. She said of the relationship: "I'm seeing somebody. It's very early days so I don't want to say anything more, but I'm happy."

In August 2017, it was announced that King would reprise her role as Carla in December that year. Her return aired on 22 December 2017.

In 2018, King appeared in four episodes of Sky One programme Sick Note as Superintendent Henchy which marked her first appearance in a Sky One production since the end of Dream Team.