The Angel's Share star was at the Royston At Work project as the group finished their studies.
Paul, originally from Barrow- field in the East End, told his life story to the young people.
The 26-year-old screen star was born to parents who were both drug addicts and he was in prison, where he got involved in an employment programme which helped him turn his life around.
Paul, who played Robbie in Ken Loach's dark comedy The Angel's Share joined the Minister for Youth Employment Angela Constance MSP to present the graduates with their qualification.
He said: "I am used to hearing young people say there is no hope, there's no chance, they have no real aspirations.
"These young people have aspirations about where they want to be in their life and it just makes me feel a little happier.
"I have walked in their shoes, they have walked in mine. I know where they are coming from."
Nine young men and two young women finished the two-year Royston at Work program-me, focused on helping them get jobs in the building trade.
They completed a six-week personal development course, which included a residential stay and the chance to do their Duke of Edinburgh Award.
A 16-week course at North Glasgow College also helped the youngsters get jobs or go onto further education.
William Brisbane, 19, of Cowcaddens had been on job seekers allowance but now has a job as an environmental operative with Glasgow City Council.
He said: "I wasn't confident, I was stressed and lazy, then this chance came up and I took it. Now I feel good about myself."
Samantha Carroll, 21, of Royston said that when she was younger she was always in trouble. Now she is on a painting and decorating course at North Glasgow College and she said the course "has changed my life."
Angela Constance MSP said projects like RAW were extremely important, adding: "We are living through difficult economic times, we know that young people are always hit the hardest in a recession, but there are things we can do that will make a positive difference."