St Marks' Church has been saved from developers' plans to turn the West End listed building into a spa.
Developer Hammer Holdings Group Ltd had plans to turn the Grade I-listed church, built between 1825 and 1828, into a luxury health treatment centre, which would include a shop, juice bar and plunge pools.
But Westminster Council's planning committee refused to grant permission to touch the North Audley Street church.
Campaign group Save St Mark's Action Group lobbied councillors outside Westminster City Hall, in Victoria Street, before the meeting.
Speaking at the meeting, committee chairman and Westminster Council's deputy leader Cllr Robert Davis said: "My committee decided to refuse this application on the grounds that this is one of the most beautiful churches in Mayfair and we believe that a building of such architectural magnificence should be available for anyone to enjoy. We believe that the restoration of this Grade I-listed building can be undertaken.
"As such, the building will continue to benefit the wider community, and we hope that funding can be found which will see the church continue to be used as a place of worship."
The planning committee - also made up of Cllrs Susie Burbridge, Steve Summers and Barbara Grahame - made a unanimous decision to refuse the planning application.
Diocese of London, the owners of the church, stopped the congregation using the building in October.
The Diocese said the church had become 'redundant' and that it had not been able to raise enough money to carry out much-needed repairs to the building.
An agreement maynow be made between the Diocese and the congregation to continue the community events which have been held at the church, including women's groups and anti-knife crime events.
Churchgoers may also now be able to continue to use the building as a house of prayer, if an agreement can be reached with the Diocese.