Boris Johnson’s party had been hoping to retain the mayoralty following their 2017 victory in the region, but Mr Norris defeated his Tory rival during the second round of voting, with 125,482 votes.
Using his victory to praise Sir Keir Starmer, who faced a series of disappointing results in council elections in England and the Hartlepool by-election, the new mayor said the party leader had “unlocked this election for Labour in the West of England”.
“Without him and his skills, his determination and him being who he is, we could not have got this result,” he added.
“People were able to listen to our arguments and be persuaded by them because of Keir Starmer. I want to thank him very, very much indeed”.
Mr Norris’s defeated his Conservative rival, Samuel Williams, who was running for the West of England mayoral role after the resignation of the party’s incumbent Tim Bowles.
Mr Bowles became the first metro mayor for the West of England Combined Authority, made up of three of the councils in the region – Bath and North East Somerset, Bristol and South Gloucestershire.
Last month, however, the prime minister ran into difficulty when he was quizzed by a reporter to name the Conservative mayor in the region during an awkward encounter at a campaigning visit ahead of the election.
Quizzed by a reporter while visiting Gloucestershire whether he was able to name Mr Bowles, the prime minister stumbled: “I’m very much in favour of powerful mayors in the West of England and elsewhere.
“But what I want to see is a stronger Conservative mayor in London and across the West Midlands and West of England and across the whole of the country.”
In a second attempt to elicit an answer to the question, the reporter enquired again: “You have a Conservative mayor in the West of England at the moment, I just wondered if you know who that person is?”
However, the prime minister — unable to summon the name of Mr Bowles — replied: “Well I can tell you I’ll be out campaigning for the West of England mayor, and all Conservative candidates throughout the week”.