The 33-year-old model was found to be more than twice the legal limit when her Range Rover Evoque was pulled over by police earlier this year
The model and Desperate Scousewives star pleaded guilty to driving while over the limit at a hearing at Sefton magistrates' court on Merseyside.
The 33-year-old was given a 20 month driving ban and ordered to pay more than £500 in fines, costs and a victim surcharge, reports the Liverpool Echo.
Harrington, of Dapple Heath Avenue in Maghull, Merseyside, was tested after being stopped on January 31 of this year and was found to have drunk more than twice the legal alcohol limit.
She was charged with driving a Range Rover Evoque on Ormskirk Road, after "consuming so much alcohol that the proportion of it in your breath, namely 85 microgrammes of alcohol in 100 millilitres of breath, exceeded the prescribed limit".
Harrington pleaded guilty to drink driving at Sefton magistrates' court on March 10 and was handed a 20 month disqualification.
That will be reduced by 20 weeks if she completes a Government-approved course before April 22, 2016.
She was also fined £400 and ordered to pay £85 costs and a £40 victim surcharge
