The British singer, who has been dating Alex since her personal trainer introduced them in 2014, exchanged vows with her fiance on Sunday (04Sep16) in Florence, Italy, in front of family friends including TV presenter pal Kate Thornton.
"I'm up & today's the day!," she wrote on Twitter before the nuptials. "Marrying the kindest & most gorgeous man I have ever known, my @alexpartakis It's like Christmas but better!
"So this just happened...," she added following the ceremony. "Mr & Mrs Partakis On cloud 9! I love you my Husband @alexpartakis."
The 33-year-old and Alex arrived in Italy on Monday (29Aug16) in preparation for the wedding.
"The lovebirds have landed in Florence," she wrote. "T-minus 5 days."
"Chilling by the pool with my fiance @alexpartakis T-minus 2days (sic) until we are Husband & Wife! #Tuscany," she added later in the week.
This is the first wedding for Heidi, who was previously engaged to British TV presenter Dave Berry. They split in 2011 after eight years together.
Before her engagement last year (15), she spoke of her desire to wed Alex.
"I try not to think about it - I could be waiting a long time," she said.
And after the engagement Heidi broke the news on social media.
"Delighted to share the news that my gorgeous @alexpartakis proposed last night!," she wrote. "Am the happiest girl alive and can't wait to be Mrs HP".
Alex added, "Am the happiest man in the World today. @Heidi_range said yes! Can't wait to spend the rest of our lives together".