Jeremy Corbyn reflected on a "difficult year" in what is expected to be his final Christmas message as Labour leader.
He called the festive period a time to reflect, as he appeared to reference his party's catastrophic election defeat.
"This has been a difficult year for many of us," Mr Corbyn said.
"We didn't succeed in delivering the change that so many people so desperately need.
"But Christmas is a chance to listen, reflect and remember all the things that bind us together: our compassion, our determination to tackle injustice and our hope for a better world."
Mr Corbyn also said it was a time of year the when "the scale of injustice and inequality is in very plain sight".
He praised those working in food banks and emergency shelters to help the less fortunate.
"While we celebrate being together, we are reminded of the many who will be alone and sadly lonely at Christmas," he said.
"But our communities are built on generosity and the solidarity that comes from that.
"So we do not walk by on the other side."
It came as the PM Boris Johnson, who will be spending his first Christmas as Prime Minister in Downing Street with his girlfriend Carrie Symonds, thanked those in the NHS, the police and other public services who would be working over the holiday.
He also thanked military personnel on deployment with the armed forces.
