Scotland's Housing Minister Kevin Stewart released statistics showing 12,343 children were part of live homelessness applications on Christmas Day 2018.
The figures were released in response to parliamentary questions by the Scottish Liberal Democrats.
The party has said the numbers are "tragic" and called for a "revolution" in social rented housing.
The number of children homeless across Scotland had been rising since the 2015 figure of 10,508, until last year when it fell by 424 to 12,858.
The local authority with the largest number of children on its live homeless applications last Christmas was Glasgow City Council at 2,475, followed by Edinburgh City Council on 2,153.
Outside these cities, figures dropped sharply, with South Lanarkshire Council having the third largest number at 796.
Scottish Liberal Democrat housing spokeswoman Caron Lindsay said: "Housing is a basic human need and it is a key responsibility of any government to ensure that people have a warm and secure home, especially at this time of year.
"These new statistics show that over 12,000 children - almost the capacity of the Hydro - are not so lucky.
"What's more, there were almost 2,000 more children homeless last Christmas compared to 2015 - a 17.5% increase. That is a tragedy."
The figures were released at the same time as Labour highlighted the rise in people citing mental health problems as a reason for becoming homeless.
The number of people citing this as the reason why they could not stay in their accommodation increased by 99% in the five years up to 2018-19, to 6,031.
Over the same period there was a 64% increase in the number of people who became homeless because of physical health problems, with this affecting 2,340 people last year.
Communities spokeswoman Pauline McNeill claimed: "The SNP's lack of action on homelessness prevention is disappointing.
"Local authorities are chronically underfunded meaning frontline services are struggling to cope with the demand for support."
She added: "The Scottish Government's commitment to rapid rehousing is of course welcome, but without investment in preventing homelessness the issue continues to grow."
But Mr Stewart said: "Scotland has some of the strongest rights in the world for anyone experiencing homelessness, including the right to emergency temporary accommodation when homeless. While this provides an important safety net, we are clear such arrangements must be for as short a time as possible and be of good quality.
"That is why we have invested £32.5 million into Rapid Rehousing and Housing First to minimise the length of time people spend in temporary accommodation.
"We also changed the Unsuitable Accommodation Order in 2017 so families with children and pregnant women are only able to stay in accommodation such as B&Bs for a maximum of seven days.
"We are proud of our record on delivering social housing. Recent statistics show that 61,356 homes for social rent have now been delivered since 2007.
"With our investment of more than £3.3 billion over this parliamentary term we'll continue to push towards our ambitious target of delivering 50,000 affordable homes - including 35,000 for social rent - and take forward our actions to end homelessness for good."