St Laurence’s Church in Upton Court Road is holding exhibitions and tours of the place of worship, which dates to the Norman era.
The event will feature bottles, preserves, gifts, cakes, craft, sideshows, raffles, and refreshments all day.
Church verger Allan James said the fayre had been running for 28 years.
He said: “It’s getting so well known in the community that everyone expects it in the first weekend of September.
“We had 2,800 people last year, so it’s a significant thing. We’re looking to see as many people as possible.”
Mr James said the church was a remarkably rural location so close to an urban centre.
He said: “The church and Upton Court House are like a time warp – you’re in Slough, and then you go into a country church.”
He said the church community was actively working to keep the building in good order, including £60,000 of restoration work when the ceiling on the south side collapsed last October.
Mr James added: “That exhausted our funds, but there’s a lot of continuing projects and stonework to do.”
Slough astronomer Sir William Herschel, who discovered Uranus, is buried in the church. He was commemorated with a stained-glass window in 2001.
The fayre runs from 10.30am to 4pm.
For more information, visit www.saint-laurence.com
Source: Slough and Langley Observer