Florence Eshalomi said she was humbled to have held the Vauxhall seat for the Labour Party.
Brexiteer Kate Hoey stepped down as Vauxhall Labour MP – a seat she had held since 1989 – in July.
Ms Eshalomi won 31,615 votes (a 63.5% vote share) – a slight increase on the 31,522 she got in 2017 – but more than enough to beat Liberal Democrat Sarah Lewis’ 12,003 votes.
Conservative candidate Sarah Bool won 9,422 votes, Green party’s Jacqueline Bond gained 2,516 votes, Independent candidate Salah Faisal won 136 votes and Brexit party Candidate Andrew McGuiness won 641 votes.
Ms Eshalomi said: “It’s time for change. I want to start by saying thank you to the residents of Vauxhall who placed this absolute honour in me.
“I feel so humbled beyond words to be elected as the new MP for somewhere I have called home all my life.
“A number of you know that this is the only place that I have ever lived so to think that a girl like me could represent this seat [she paused] is great.
“Putting yourself forward for election in this current climate is very difficult, especially as fellow women.
“There is a lot of hate, there is a lot of angriness and we have got to remember an MP was killed doing the job she loved, so I salute anyone putting themselves forward for public office.”
In June 2016, Labour MP Jo Cox was killed in a hate crime in Birstall, West Yorkshire.
The elected Labour MP paid tribute to the outgoing MP Ms Hoey.
She recalled her being elected when she was just eight-years-old and commended Ms Hoey for her great work.
She highlighted her constant re-election must have meant she was doing a good job.
Although the two had differing views on the European Union, she described the former Vauxhall Labour MP as a diligent, hardworking character who stood up for her residents.
She said: “I hope to follow in that, I will be a voice for the residents across Vauxhall.
“A voice for those people that I have spoken to over the last six weeks. A voice for those people who are using food banks.”
The Labour MP is the former chair of the London Assembly Transport Committee and has been a member for Lambeth and Southwark since 2016.
The turnout in Vauxhall was higher than the 2017 General Election with 56,333 people coming out to vote in comparison to 55,042 in 2017.
The mother of two will be the first MP to have gone to school in Lambeth since the seat was created in 1950.
She paid tribute to the people who helped her along the road to success. The hardworking activists, electoral staff, Labour members for the globalisation of her campaign and her agent, Martin Bailey.
Supporter Mohammed Seedat said of Ms Eshalomi on Twitter: “A bright ray of hope on a gloomy night. She will be a great parliamentarian.”
Ms Eshalomi was upset to see Labour colleagues lose their seats in this General Election.
Miss Eshalomi said on Twitter: “Thank you Vauxhall residents for this honour to represent you and for putting your faith in me.
“It was time for change. I’m truly gutted for candidates that were not re-elected.
“The people of Vauxhall need a Labour Government and I will continue fight for a fairer society for us all.”
She concluded: “I am proud to have stood on the Labour manifesto which offered real hope and change.”