Sir Bob Geldof is thought to be leading tributes to his daughter at the private service in the same church where the funeral of her mother Paula Yates was held.
A host of well-known personalities were in attendance at St Mary Magdalene and St Lawrence church in the village of Davington, near Faversham in Kent.
They included Sarah Ferguson, supermodel Kate Moss, musician and television personality Jools Holland, former Rolling Stones bassist Bill Wyman and BBC Radio 1 Breakfast Show presenter Nick Grimshaw.
Also in attendance to pay their respects were journalist Mariella Frostrup and model and television personality Jo Wood.
Just before 1pm a hearse carrying Peaches' coffin arrived outside the church, which is next to Sir Bob's Davington Priory country estate, where Peaches grew up.
The coffin was painted sky blue, with clouds and flowers along the side and a picture of Peaches' family and pets at the back.
Dozens of locals gathered outside the church, which is where the 25-year-old socialite married musician Tom Cohen, the father of her children, in 2012.
It is also where television presenter Yates married Geldof in 1986.
Yates' funeral was held there after she died from an accidental heroin overdose in 2000, aged 41.
There were bouquets and cards left outside the entrance to the estate's driveway.
Peaches' ashes are expected to be scattered in the property's garden where she played as a child, according to reports.
Written in chalk on the church's wall, a message read "RIP Peaches".
Mystery still surrounds the sudden death of Ms Geldof on April 7.
Her body was found at the home she shared with her husband and their two young sons, Astala, 23 months, and 11-month-old Phaedra, in Wrotham, Kent, after officers were called "following a report of concern for the welfare of a woman".
Former Boomtown Rats singer Geldof paid tribute to his daughter alongside his partner Jeanne Marine and Ms Geldof's sisters Fifi Trixibelle, Pixie and Tiger, saying she was the "wildest, funniest, cleverest, wittiest and the most bonkers of all of us".
Kent Police said it was being treated as a "non-suspicious, unexplained sudden death".
An inquest is not expected to be opened and adjourned by the coroner until after the results of toxicology tests are known.
At around 2.40pm the hearse which had brought Peaches' remains to the funeral left the Davington Priory estate without the coffin.
Mourners started to leave the estate, some carrying the order of service with a portrait of Peaches on the front and another picture of her family on the back.
The Duchess of York was driven off in a chauffeured green Bentley and waved to onlookers as she left.
Kate Moss and her husband Jamie Hince left together after they were picked up in a black Mercedes. They were followed shortly afterwards by Jo Wood.