The Swansea Young Single Homeless Project has become part of its fellow homelessness charity Llamau.
The organisations, which completed the merger this month, said the move would enable SYSHP’s services to continue and allow young people in Swansea to access new opportunities through Llamau’s education, training and employment services.
A spokeswoman for the charities said the merger would not result in any job losses or redundancies and the charities’ services would continue as normal.
Three SYSHP trustees have joined the now 12-strong Llamau board.
Llamau, which had an income of £10.7m in the year to the end of March 2018, is considerably larger than SYSHP, which had an income of £1.3m over the same period.
Frances Beecher, chief executive of Llamau, said: "SYSHP have been supporting some of the most vulnerable young people in Swansea for more than 30 years, and SYSHP colleagues know and understand Swansea.
"It is vital that organisations work with a strong understanding and knowledge of local issues. We’re looking forward to continue working in close collaboration with SYSHP’s existing partners to ensure young people in Swansea continue to receive the highest-quality support."
Liz Slade, director of SYSHP, said: "We will be able to continue to deliver high-quality, professionally led services to young people, in partnership with the local authority and other organisations in the area.
"Not only will the merger provide colleagues with a more effective infrastructure, but young people will also be provided with additional opportunities to develop and thrive."