The 52-year-old Spice Girls singer - also known as Mel C and Sporty Spice - and the model-actor-and-screenwriter, are said to have tied the knot at Country House Cumbria in the Lake District, North West England, on Saturday, the Mail on Sunday reported.
According to the publication, Melanie's bandmates, Geri Halliwell-Horner, Melanie Brown/Mel B, and Emma Bunton, attended, but Victoria Beckham, was absent due to being in the USA with her 51-year-old husband, ex-football player David Beckham, for the 2026 FIFA World Cup.
However, it has been reported that Victoria designed Melanie's white, backless, floor-length wedding gown.
"It was a gift from Victoria; they are really close. Victoria would have loved to have been there if she could," a source told the Mail on Sunday.
"It was her great pleasure to make the dress for Mel.
"She was sad she couldn't be there because she's in the US with David and, of course, the World Cup plans had been set for a long time.
"But she was wishing her all the best from afar for Mel's special day."
Melanie's 17-year-old daughter Scarlett - whom she had with her ex-partner, property developer Thomas Starr - was her bridesmaid.
The Mail on Sunday reported that guests looked "alarmed" as a herd of cows from a nearby farm ran towards Country House Cumbria - owned by actor Ben Forster, 45, who starred alongside Melanie in the musical Jesus Christ Superstar in 2013, and property developer Paul Longman - while the Wannabe hitmaker and Chris delivered their vows.
"Mel and Chris wanted an understated wedding; she didn't want a big flashy day but something smaller and very classy" a source said.
"Mel swore she would never get married, having a big do wasn't really for her.
"It is the perfect venue for them, totally out of the way but in the most beautiful place, and everyone had the most fantastic time.
'Victoria couldn't be there, but she loves Mel, and she will have made sure that she sent a beautiful present."
The pair has been in a relationship for around two years after meeting on celebrity dating app Raya.
Melanie has previously spoken openly about never believing marriage would form part of her future.
"I've never, never wanted to marry. Maybe marriage works for some people, but maybe to think it works for the majority is an old-fashioned notion," she told The Sunday Times in 2022.
However, speaking to the same newspaper earlier this year, she revealed she had changed her perspective.
"You know what? (Marriage is) something I didn't think would be part of my story. But I'm so happy with Chris.
"Maybe it is something that will be in my life. I just think, just do all the things. Do you know what I mean? Have all the experiences."