The 59-year-old was arrested in Hertford earlier this year after police officers caught her driving under the influence of alcohol.
Appearing in court today, the EastEnders actress pleaded guilty to the charges but, according to reports, asked to keep her license because of 'special circumstances'.
The Mirror claims that Gillian insisted she needed to be able to drive her husband to get treatment for his cancer.
But the judge dismissed her request, enforcing the ban and ordering Gillian to pay a £3,500 fine plus charges.
The judge said: "Hertford town centre is very busy on a Saturday night, with so many clubs, bars, restaurants and pubs and taxi ranks in close proximity to the area you were in.
"Taking into account the local knowledge we are satisfied there would have been a real danger to pedestrians and other road users for you driving your vehicle when you were significantly over the limit.
"We do not therefore find any special reasons."
It was confirmed last month that Gillian will return to EastEnders as Kathy Beale full-time, following a brief appearance during the live episode in February.