It was organised by the Reverend Rachel Phillips (see photo) at the Priory Church of St Peter in Dunstable, Bedfordshire.
The Church of England rector maintains that "Christmas is not just for Christmas".
"We celebrated as Dunstable has never done before," she said.
The outdoor event included traditional carols, a small nativity play and a visit from Father Christmas.
"He's not that busy at this time of year," Ms Phillips said.
The event was not just to make up for the church not being able to hold its usual carol service in December because of coronavirus regulations.
"Last December we weren't able to celebrate as we normally would, so we're doing it now," Ms Phillips said.
"But there is a serious point here, which is, that what Christians celebrate at Christmas is not just for Christmas - it's not just for one day."
About 100 people turned up wearing their Christmas jumpers and sporting Santa hats.
Children dressed as their favourite "nativity character" and picnics were eaten - complete with turkey sandwiches and mince pies.
"The weather was a lot more Christmas jumper friendly than the hot temperatures we had last week," Ms Phillips said.
"The children were so excited, seeing their faces when Father Christmas appeared was just lovely. It made their Christmas."