In a video posted to Twitter, Johnson acknowledged that Christmas Day is “first and foremost, a celebration of the birth of Jesus Christ.”
“It is a day of inestimable importance to billions of Christians the world over,” he added.
He continued: “Today of all days, I want us to remember those Christians around the world who are facing persecution. For them, Christmas Day will be marked in private, in secret, perhaps even in a prison cell.
“As prime minister, that’s something I want to change. We stand with Christians everywhere, in solidarity, and will defend your right to practice your faith.”
Johnson also thanked those working in public services on Christmas day, particularly members of the NHS and Armed Forces.
“As many of us are enjoying a break at this time of year, let’s not forget all those who have selflessly put their celebrations on hold,” he said.
“On behalf of the whole country, I want to say a huge thank you to our amazing NHS [National Health Service] staff … many of whom will be working throughout the holidays to take care of us.”