More than 800 people are expected at Christ Church Cathedral this morning.
Police officer Andrew Harper was killed on August 15 near the village of Sulhamstead in Berkshire.
The 28-year-old newlywed from Oxfordshire died from multiple injuries after being dragged under a van.
His funeral is being held today (14/10) at Christ Church Cathedral on St Aldate's, at 11am.
Thames Valley Police said while it is a private funeral, the public can "pay their respects along the processional route".
However the family has requested that no flowers are brought to the cathedral or to the procession.
Craig O'Leary, chairman of Thames Valley Police Federation, said Pc Harper was a "hero", who was loved by his family, friends and colleagues.
In a statement, Mr O'Leary said: "Pc Andrew Harper loved being a police officer. It is our sad duty today to pay our last respects to him and support his wife Lissie, his family and his friends at his funeral.
"This has really hit us all hard and shocked everyone in the whole police service."
Police have warned of some disruption in the city due to road closures between 8am and 12.30pm for the funeral procession.
St Aldate's will be closed from the city centre to its junction with Speedwell Street.
There will also be road closures on The Plain, Magdalen Bridge and High Street, police said.
Pc Harper's family has asked for any donations to be made to the Tiggywinkles Wildlife Hospital on Aston Road, Haddenham, or the Blue Cross re-homing centre on London Road, Lewknor.
Meanwhile, thousands of people have signed up to take part in a "ride of respect" in PC Harper's memory on October 27.
The motorcycle event is due to set off from RAF Benson to Abingdon Airfield in Oxfordshire.
Organiser Sian Sloper, from Caversham, said 2,240 people had registered to take part so far.
PC Harper had been married to his partner Lissie for just four weeks when he died.
She described him as "the kindest, loveliest, most selfless" person.
As a mark of respect, flags across Thames Valley Police are flying at half-mast today.
Henry Long, 18, from Mortimer in Reading, and two 17-year-old boys, who cannot be named because of their age, have been charged with murder and conspiracy to steal a quad bike.
Thomas King, 21, from Basingstoke, is also accused of conspiracy to steal a quad bike.
Jed Foster, 20, was also accused of Pc Harper's murder, but prosecutors dropped the charges against him as there was no longer a realistic prospect of conviction.