The 29-year-old, who has more than 99 million subscribers on the online video site, announced the news on Twitter on Tuesday.
He wrote: “We are married!!! I’m the happiest I can be.
“I’m so lucky to share my life with this amazing woman.”
The couple, who live in Brighton with their pugs Edgar and Maya, have been together for eight years.
They tied the knot at London’s Kew Gardens on Monday.
PewDiePie, whose real name is Felix Kjellberg, has the second most-subscribed YouTube channel in the world.
The Swedish former economics student mainly posts comedy-formatted shows which attract millions of views.
Bisognin had her own fashion YouTube channel called CutiePieMarzia up until 2012, which focused on fashion, beauty, DIY, books and movies.
Since 2015 she has launched several lines of fashion and design merchandise.
She posted on Instagram after her wedding: “Yesterday, the 19th of August – after exactly 8 years since we met – we celebrated our wedding with our closest friends and family.
“It was the most beautiful day, which I will treasure forever, I am so thankful for all the people that made time to attend the event and helped us celebrate our marriage.
“I feel like the luckiest person and I’m so full of love.
“Incredibly ecstatic to be able to call Felix my husband for the rest of our lives.”
The couple first met after Bisognin’s friend recommend that she watch “this idiot playing video games”.
They started dating in 2011 after she emailed him and told him that she found his videos funny.
The couple lived in Sweden and Italy before settling in the UK.
PewDiePie has been controversial. He was forced to apologise to fans after using a racial slur while live-streaming a video game.
Disney and YouTube said they would stop sponsoring his channel after some of his videos used Nazi imagery and anti-Semitic jokes.