The coverage map was created based on data from the UK's leading service providers as well as the watchdog's signal tests around the country.
It measures call quality and data connectivity both indoors and outdoors for each area, along with geographic variables such as valleys and hills that could affect signal strength.
Users can search for their local area by entering their postcode or zooming into an area on the map.
"Access to reliable mobile phone coverage used to be a 'nice to have'," said Ofcom's chief technology officer Steve Unger. "Now it's essential to many people's lives."
Ofcom is seeking community feedback to help improve the accuracy of the service, asking users to get in touch if their coverage is significantly different to the map.