Champion studied Psychology at Sheffield University. Before entering Parliament, she ran art workshops and was employed as the Chief Executive of a children's hospice in Rotherham. Champion was first elected to Parliament at the 2012 by-election. She was given the role of Shadow Minister for Preventing Abuse in the Shadow Cabinet of Jeremy Corbyn in September 2015, but resigned in June 2016, following a vote of no confidence in Corbyn, but returned to the frontbench in July 2016. In October 2016, she was appointed to the role of Shadow Minister for Women and Equalities in addition to her other post.
In August 2017, Champion resigned from her post following criticism of an opinion piece she wrote for The Sun that discussed what she termed the "problem" of white girls being raped and exploited by British Pakistani men, and which fellow Labour MP Naz Shah described as "incendiary and irresponsible".
Champion graduated with a BA degree in psychology from the University of Sheffield in 1991. After working as a volunteer at Sheffield's St Luke's Hospice and running art workshops at the city's Abbeydale Road Secondary School she gained full-time employment, running Rotherham Arts Centre from 1992–1994. Champion then worked as an Arts Development Officer for Ashfield District Council. She ran the Chinese Arts Centre in Manchester from 1996 to 2008, and was the Chief Executive of the Bluebell Wood Children's Hospice in North Anston, Rotherham from 2008 to 2012.
In November 2012 she was selected to be Labour's candidate for the upcoming Rotherham by-election, which was triggered by the resignation of the constituency's MP, Denis MacShane. Champion was chosen to stand for Parliament from a shortlist chose by the party. She was elected as MP for Rotherham on 29 November with 9,866 votes (a 46.25% overall share of the vote). Jane Collins of the UK Independence Party was second with 4,648 votes (21.79%), achieving that party's best result in a by-election. Labour achieved a majority of 5,218 (24.46%), an increase in terms of percentage from Rotherham's 2010 general election result, but a decrease in the actual number of votes cast. Champion is Rotherham's first female MP.
In an interview with BBC Radio Sheffield on 30 November 2012, Champion said that she does not regard herself as being a career politician: "There are some people who from the moment they were born wanted to be a politician. Whereas for me, since I started working I've always been working with the community and I want to carry on doing that."
In a 2014 BBC interview, Champion admitted that she rarely attends Prime Minister's Questions.
On 7 May 2015, Champion was re-elected as the Member of Parliament for Rotherham with a 52.5% share of the vote. She secured 19,860 votes, increasing her majority by over 3,000. She was one of 36 Labour MPs to nominate Jeremy Corbyn as a candidate in the Labour leadership election of 2015.
Champion was formerly a member of the Transport Select Committee, Parliamentary Private Secretary to Shadow Education Secretary Tristram Hunt, Chair of the All-party parliamentary group (APPG) on Victims and Witnesses, Chair of the All-party Parliamentary Group on Choice at the End of Life, and Co-chair All-party Parliamentary Health Group.
Champion was appointed Shadow Minister for 'preventing abuse and domestic violence' in 2015. She resigned from this position on 28 June 2016, in the wake of criticism of Jeremy Corbyn's approach towards the EU referendum following a vote to leave the EU.
In November 2013, it was announced that Champion, in partnership with children’s charity Barnardos, would lead a cross-party inquiry to investigate the effectiveness of the Sexual Offences Act 2003 in tackling child sexual exploitation and trafficking within the UK.
Champion conducted an inquiry with Barnardo's in 2013 to investigate how effectively children are protected from sexual exploitation by the law in 2013. Later, in July 2014, and as a result of her inquiry, Champion managed to make an amendment to the Criminal Justice and Courts Bill that allowed a person caught arranging to meet a child for sex to be convicted straight away. Previously, the person had to be caught twice.
In January 2016, Champion launched a campaign called Dare2Care that focuses on preventing child abuse and the normalisation of violence in young people's relationships The campaign has launched a website, putting tools and resources for young people, parents and professionals in one place. These are intended to help better inform people on how to tackle child abuse and relationship violence. Later in March she publicly criticised the Prime Minister over a failure to carry out pledges made the previous year in tackling with child abuse. Champion criticised the lack of progress over a national child abuse task force and a whistleblowing portal that had no 'taskforce to blow to' as well as the failure to begin a consultation on extending the offence of wilful neglect to children's social care, education and councils.
In response to the Jay Report released in August 2014 which found 1,400 victims of child sexual exploitation in Rotherham between 1997 and 2013, Champion applauded the council for apologising and accepting the report. The following week Champion asked a short question to the Home Secretary, saying she was angry, and asked for necessary resources to solve the problems.
In October 2014, Champion secured additional funding to appoint Jayne Senior, a specialist in child sexual exploitation, to support the 1,400 victims of child abuse in Rotherham.
In November 2014, Champion asked the Prime Minister to support Rotherham’s victims and to ensure that procedures are in place to prevent such widespread abuse happening again. The Prime Minister replied in part that the Home Office was leading "this important effort" in getting departments to work together.
In December 2014, Champion took a Ten Minute Rule Bill to Parliament asking for the mandatory publishing of figures of the pay gap between men and women in any company of over 250 employees. The Bill was overwhelmingly supported by MPs, with 258 voting in support and just 8 voting against.
In July 2015 the Prime Minister, David Cameron, announced the Government would be adopting the measures put forward in Champion's Bill.
Champion was appointed as Shadow Minister for Preventing Abuse by Jeremy Corbyn in September 2015.
In June 2016, Champion resigned as shadow Home Office minister focusing on women, equality and domestic violence after Labour MPs passed a motion of no confidence in Jeremy Corbyn. However, the next month she returned to the frontbench in the same post.
In September 2016, it became known that Champion had been cautioned by police in 2007 after a violent altercation with her husband while they were about to divorce. Champion admitted she had "lost control" and said: “I’m not proud of what happened and I accept I was in the wrong but I have nothing to hide. I lost control after being provoked for years and for that I am sorry but I felt extremely vulnerable at that moment".
In October 2016, the leader of the Labour Party Jeremy Corbyn appointed Champion to the role of Shadow Minister for Women and Equalities. In November 2016, Champion launched Dare2Care, a National Action Plan for Preventing Child Abuse and Violence in Teenage Relationships. Among Champion's key recommendations is the compulsory introduction of resilience and relationships education for all children from Key Stage One.
In August 2017, on BBC Radio 4's Today programme she asserted that "more people are afraid to be called a racist than they are afraid to be wrong about calling out child abuse". Her statements were followed by an opinion piece for The Sun titled "British Pakistani men ARE raping and exploiting white girls ... and it’s time we faced up to it". The article went on to suggest that "Britain has a problem with British Pakistani men raping and exploiting white girls". Fellow Labour MP Naz Shah criticised Champion's statements, describing the headline as incendiary and irresponsible, and arguing that 90% of child sexual abusers were white men.
A few days later, Champion distanced herself from The Sun article, which she said should "not have gone out in my name", asserting that beginning of the article had been altered by the newspaper's staff resulting in the piece being "stripped of nuance". The newspaper said the article's final form had been approved by her team, and later produced an email from one of her aides confirming she was actually "thrilled" by the article. Champion resigned from her post on 16 August 2017.