The 33-year-old was breathalysed by police as she returned to her home in Chelsea, London. She was found to be over the limit and arrested, The Sun reports.
"Georgie is utterly devastated as you can imagine. She held her hands up immediately," a source told the paper. "She'd been at a friend's house for lunch and had had a few drinks early on.
"Georgie stopped drinking after a while and when it was time to go home she figured she would be okay. She was not staggering around drunk or anything. If she thought she was drunk she would not have driven."
Thompson, who has worked for Sky Sports News since 2001, was said to be worried about the reaction of her bosses, who she informed of the incident shortly after her release.
The Sky1 A League Of Their Own team captain split from boyfriend Declan Donnelly earlier this year. Speaking in June, she admitted that it was tough to go through a "painful break-up when you're in the public eye".
A spokesperson for Thompson, who will appear in court next month, said: "We can confirm she was pulled over for being over the limit at the weekend."