The First Minister said this date would allow the Scottish people to make a "considered" decision on Scotland's future within the United Kingdom and that the Scottish people faced "their most important decision for 300 years".
By confirming that the referendum will be Autumn 2014 will allow all the necessary legislation required to authorise it to be passed and for proper preparations to be made with a referendum bill being introduced to the Scottish Parliament in January 2013.
He added:
"The date for the referendum has to be the autumn of 2014. That's because this is the biggest decision that Scotland has made for 300 years. If you are going to do things properly and have the debate in the way it must be had then that is the date that we are going to move towards."
The Scottish Government will launch a consultation on the referendum later this month.
