The City of London Academy in Lynton Road is one of four schools hosting day centres for homeless people this Christmas run by the charity Crisis.
The Bermondsey day centre opened on Wednesday and will be in operation between 9.30am and 9pm until 30 December.
Crisis Christmas has been operating for 38 years, running centres across London including specialist venues for those with high support needs.
Crisis Christmas provides homeless and vulnerably housed people with a range of services, including housing and benefits advice, counselling, hairdressing, medical, eye and dental care, as well as healthy food and shelter.
At the City of London Academy Crisis Christmas is offering a full range of services and a restaurant catering for 150 people.
"The experience of homelessness de-skills and isolates," says Leslie Morphy, Crisis chief executive. "Learning new skills or regaining lost ones is central to tackling homelessness.
"Thanks to the support of the colleges we can give our guests the opportunity to take advantage of vital services in an inspiring, educational setting.
"For many homeless people, this will be the start of their journey with us as we continue to support them throughout the year at Crisis Skylight – our award-winning education, training and employment centres."
Most guests arrive at and leave the centre in minibuses that run from locations around the area including St John's Waterloo, London Bridge and Bermondsey stations.
A constant neighbourhood patrol of volunteers is provided throughout the hours of operation.
Last year Open Christmas opened eight centres which attracted 950 visitors.
Crisis is the national charity for single homeless people. To find out about volunteering opportunities, go to www.crisis.org.uk/volunteering