In Edinburgh, veteran actor Brian Cox spoke to crowds in West Princes Street Gardens and in NY, film star Will Smith delivered a speech.
He then called out for anyone who may want to support the initiative, saying they could do so at a local branch and make donations. She recently visited California, where an increase in income inequality and a lack of affordable housing have combined to push many people into homeless encampments. He said he found it hard to believe that asking for a job at the sandwich shop years ago had wound up making him a part of an worldwide campaign to raise money and awareness for trying to end homelessness.More news: Why Camila Cabello did not want to kiss Shawn Mendes
The money from previous years has been used to fund 831 flats across Scotland for homeless people as well as the Social Bite Village in north Edinburgh.
"The line between having a home and homelessness for many families is so thin", she said, before reading a "bedtime story" to more than 2000 people assembled in bright orange sleeping bags in London's iconic Trafalgar Square. Olympic cyclist Chris Hoy and singer Rag'n'Bone Man also took part in the London event.
Mr Littlejohn, said: "I am blown away by the response to The World's Big Sleep Out and incredibly excited to have 50 cities all over the world taking part". In four designated plazas in Times Square, some 900 people joined to raise awareness about homelessness.More news: Australian Batsmen Take Hard Blows To Body On Dangerous MCG Pitch
"We can also send a message to the world's political leaders that urgent action is required to address the human suffering that we each witness on our streets every day".
"It's not everyone's decision to end up on the street", he said.
Actor Will Smith rapped the theme song to his 90's hit show "Fresh Prince of Bel-Air" in Times Square Saturday night for over 1000 shivering souls who braved the freezing temperatures in a "sleepout" to raise awareness for homelessness.More news: House Judiciary Committee to Hear Evidence as Impeachment Vote Nears
"I'd like to encourage anyone who cares about this issue to get involved by sleeping out, in solidarity with those who have no choice".