The Spice Girls singerMel B and Rory McPhee are currently on a waiting list for the prestigious venue, which Mel will be allowed to marry in as she received her MBE (Member of the Order of the British Empire) in 2022 for services to domestic violence victims.
She told The Sun newspaper: "As I have an MBE I am allowed to marry at St Paul's. They only do a small number of weddings a year so we are on the waiting list".
Mel, 48, explained that she and Paul had to meet with the chaplain of St Paul's because she is twice-divorced.
The star - who was married to Jimmy Gulzar from 1998 to 2000 and Stephen Belafonte from 2007 to 2017 - said: "Because I have been married twice before we talked about that. I was very open and honest. I take marriage seriously and am actually very traditional. I spoke about how I was married for 10 very abusive years. Before the conversation even ended they said they would approve us. I keep thinking how proud my dad Martin, who died in 2017, would have been".
While the Spice Girls - Geri Horner, Victoria Beckham, Emma Bunton and Mel C - have all been invited to the wedding, Mel insisted they won't be bridesmaids.
She quipped: "They won't be bridesmaids though, we are all too old".