After an hour's labour, the 42-year-old mum gave birth to a son named Archie - and has vowed it's their last.
Sue, who starred with her family and husband Noel, 46, in Channel 4's 19 Kids and Counting, was induced two weeks early at Royal Lancaster Infirmary. Speaking to The Sun, she said: 'I had about an hour of contractions, a few pushes and he was out.
'I managed on gas and air. But the pain is still just as intense so glad he was out. I can't fault the hospital - all the midwives know me now.'
After vowing to have no more children, Sue said: 'We're happy to be finishing on a nice even number. I'm just chuffed he is here safe and sound. It's strange knowing you're not going to have anymore.'
Sue explained that their 23-year-old daughter Chloe had said: "I believe you now."
'I don't think she did before,' she admitted. 'But because I've said [this is the last time] a few time now she does.'
Despite the declaration that the Radfords will not expand their family any further, Noel has revealed that he won't have the snip. The pie firm boss said: 'It was going to end at some point.
'We both think this is it. I feel sad in a way but now we get on and enjoy the kids.'
Noel had a vasectomy during Sue's ninth pregnancy, but he had it reversed when the couple longed for more children.
Baby Archie is the couple's 11th son and joins the ranks of siblings Chris, 28, Sophie, 23, Chloe, 23, Jack, 20, Daniel, 18, twins Luke and Millie, 16, Katie, 14, James, 13, Ellie, 12, Aimee, 11, Josh, ten, Max, eight, Tillie, seven, Oscar, five, Casper, four, Hallie, two, and Phoebe, 13 months.
Sue sadly suffered a miscarriage in 2014 at 23 weeks pregnant when she lost a son, Alfie.