His family have confirmed it will take place at Christ Church Cathedral in St Aldate's.
PC Harper was killed while responding to a burglary in Berkshire in August.
The Abingdon-based officer, who'd recently got married, was dragged under a vehicle and possibly hit by a police car.
His funeral is now set to take place on 14th October and will be private, but Thames Valley Police says there will be a chance for the public to pay their respects during the procession.
The processional route and road closures, will be announced closer to the date.
A statement from Thames Valley Police said: "Andrew remains in our thoughts every day and we are all committed to honouring his memory."
Three teenagers and a 20-year-old man have been charged with Andrew Harper’s murder.
They are due at the Old Bailey in London in December for a plea hearing.