Kate Osborne, currently a North Tyneside councillor, was elected with 18,363 votes in a fight for the vacant seat of former MP Stephen Hepburn.
Hepburn had represented the area for more than two decades but was barred from standing as a Labour candidate by the party’s National Executive Committee.
He had been suspended from the party since October over historic sexual harassment claims.
Although Labour successor Osborne stormed to victory against seven rival candidates, the win represents a dent in Labour’s 2017 majority.
The majority was 7,120this time round, down from 17,263 two years ago.
Reacting to her victory, Ms Osborne said said she was looking forward to standing up for Jarrow on the national stage.
“It’s a great honour to be the first woman MP here since the great red Ellen Wilkinson [1935-1947] who was of course a great socialist and trade unionist,” she said.
“We stand on the shoulders of giants like her and I will work hard to be a strong voice for the people of Jarrow constituency both here and in Westminister.”
Ms Osborne previously hit the headlines after posting a parody image on social media during the 2017 election campaign of then PM, Theresa May, with a gun pointed at her.
She has since apologised for the post and speaking before the deadline for candidate nominations this year, she said she wanted to “move on” from the incident.
Jarrow’s new MP added that she looked forward to working with South Shields Labour MP, Emma Lewell-Buck, in “making South Tyneside a better place to live and to work.”
The result follows several weeks of campaigning in the North East with visits from major party figures and even prime minister Boris Johnson.
Conservative candidate for Jarrow, Nick Oliver, came in second place with 11,243 votes followed by the Brexit Party’s Richard Leslie Monaghan with 4,122.
Behind him were independent candidate John Robertson with 2,991 votes, Lib Dem, David Wilkinson, with 2,360 votes and James Milne, who polled 831 votes for the Green Party.
Independent, Shaun Sadler, also took 614 votes while Social Democratic Party candidate, Mark Anthony Conway, won 212.
A total of 40,827 people cast their votes this year, with a overall turn-out of 62.7% compared to 66.5% two years ago.
Runner up Nick Oliver, a cabinet member on Northumberland County Council, said he was pleased with the result.
“The Conservative vote share has gone up which I’m really pleased about and the Labour Party vote share has completely tumbled,” he said.
“I think that sends out a strong statement that the Labour Party can’t be complacent and we’re making inroads, a blue wedge in a red wall.”
He added: “I think it looks like we’re finally going to get Brexit done, it looks like our party is going to have a huge majority right across the country and we will be able to get it done and get on with the important things.
“Investing in health, investing in schools and sorting out and building a strong economy.”