Charity UK Youth polled youth workers and found that 82 per cent felt loneliness was a big issue for the teenagers and young adults they worked with.
Despite this almost three quarters (73 per cent) said young people do not actively seek help with the problem.
However, just 15 per cent of those surveyed by UK Youth said their youth organisation offers specific programmes to counter loneliness.
In its A Place to Be report, UK Youth called for extra funding for youth services so they can better support lonely young people. It also recommended the creation of a "clear strategy" that includes a simple definition of what youth loneliness is.
"Youth loneliness is one of the biggest issues facing young people across the country," says Phil Sital-Singh, head of impact and learning at UK Youth.
"Local youth organisations are - and have always been - well placed to be part of the solution. If the recommendations in our report are taken forward, local youth organisations could make a substantial positive difference in the fight against youth loneliness."
The Department for Digital, Culture, Media and Sport is currently developing a loneliness strategy that will address issues affecting young people following a consultation that ended last month.
UK Youth also recommended the development of tools youth workers can use to help lonely young people. It also called for more collaboration between youth workers, social workers, health workers and schools on the issue.
The research, which was funded by the Co-op Foundation, also found that youth workers said social media platforms can make young people feel lonelier. It states: "Young people can equate social connection and support with social media ‘likes' and ‘follows'. This is publicly available information which can set young people's expectations of social response online very high - and have them dashed just as quickly if they are not met."
UK Youth's report was based on a survey of 152 youth workers in England and in-depth interviews with 12 practitioners. The charity also held three focus groups involving a total of 33 youth workers to inform its report.