The former Spice Girl tied the knot with Formula One Red Bull Team Boss Christian in Woburn, Bedfordshire in May this year.
Appearing on ITV today, the loved up singer said: "People talk about their wedding day and until you get there you don't know what it will be like, but it truly was the happiest day of my life. It was so amazing!"
Geri admitted it was "weird" to use the word 'husband' and confessed she hadn't wanted to marry anyone until she met Christian.
"My mother got divorced so it kind of put me off a bit, if I'm honest. And I hadn't met anyone where I felt it was right. It wasn't until I met Christian. When I met him, I automically knew. I said it to my friend, 'I think I've met the man I want to marry.'"
Geri revealed the couple had a mini honeymoon in the mountains outside Cannes as Christian was in Monaco after their wedding for the Grand Prix.
"It's not dissimilar to the music industry," she said of Christian's schedule. "You're on tour in a way but with cars. That can be lonely. I remember it myself. I try to be supportive and go to races when I can but I have a daughter in school."
The singer also said she and Christian had cars in common: "My late father was a second hand car dealer and he used to take me to races as a little girl. The first time I got a bit of money from my record deal, the first thing I bought was an old, gorgeous car. I've always been into cars."
Geri was on the show to raise awareness for breast cancer diagnosis in her role as patron for Breast Cancer Care, which is running a campaign called New Days, which is a programme that helps people through the diagnosis and treatment process.
"It's reminding everyone Breast Cancer Care exists and is there for you," she said.