ABC journalist Kerry O'Brien has been banned from driving for three months for speeding more than 30km/h over the limit in Sydney's south-east.

A speed camera detected the offence at the intersection of O'Riordan and Coward streets in Mascot in August.

In the Downing Centre Local Court today, O'Brien was disqualified from driving for three months and handed a $250 fine.

O'Brien, 66, began presenting the ABC's investigative program Four Corners in 2011 after 15 years presenting The 7.30 Report.

AAP