Mrs May plans to join the churches in her Maidenhead constituency who lay on lunch and entertainment for older residents who would otherwise be on their own.
She has also revealed that she will go to both midnight mass on Christmas Eve and a service on Christmas Day morning.
As the daughter of vicar the PM told the Radio Times she was raised with Christmas revolving around the church.
"I had to wait until my father had finished his services before I could open my presents. It felt like a very long wait," she said.
Mrs May has also revealed how she will spend Christmas this year. She wants a "nice Agatha Christie to curl up with".
"I always like to see Doctor Who on Christmas night, if possible, and a nice Agatha Christie to curl up with. David Suchet was a great Poirot - he got him to a T," she said.