Jimmy Carlson, 64, from Islington, north London, has been appointed OBE for helping to improve services.
The former alcoholic became homeless after he was discharged from the Army.
Doctor Daniel Moynihan, who runs 13 academies across London, has been knighted, while Emma Colyer has been appointed MBE for charity work.
Mr Carlson served with the Royal Pioneer Corps (RPC) - which later became part of the Royal Logistic Corps - for five years.
When he was discharged in 1973, he became an alcoholic and lived rough on the streets and in hostels until 1996 when he stopped drinking.
Since then he has worked with Groundswell, a self-help organisation for the homeless, and has also helped to bring homeless people together with government ministers.
Mr Carlson has also raised £100,000 for The Haven, a club where people in recovery from substance misuse can meet in an alcohol and drug-free environment.
He said he was humbled to receive the honour.
"I have been to the very bottom and never would have imagined this day then.
"Lots of people have helped me on the way and I can only hope that my story can inspire others - the same way I have been helped."
He added: "My message is, 'never give up on anyone'. You would have walked over me in the street 15 years ago and thought I was a lost cause, just another drunk.
"However, I picked myself up and turned my life around and I have gone on to make a decent contribution to my community."
Metropolitan Police PC Mark Edwards, who helped raise more than £350,000 for terminally ill children, has been appointed an MBE.
PC Edwards ran a series of marathons in New York and took on other challenges to help raise money for Jack Brown, the seven-year-old son of two of his colleagues, who needed specialist treatment in New York.
Jack, who suffered from neuroblastoma, died in 2009, but the officer has continued to raise funds for children with cancer.
He said: "When my wife told me I'd got an MBE I nearly fell off my chair. This award is for the whole team who has helped raise the money - not just me."
A 74-year-old woman, Jane Warwick, also received an MBE for what the Met described as her "tireless work alongside police" in Lambeth to help set up a firearms and knives amnesty in 1995, which was "incredibly successful".
Others honoured include Ruth Owen, from the Victoria-based charity Whizz Kidz, who has been appointed OBE; Paul Elliot MBE now becomes a CBE for services to equality and diversity in football while Maxine Room, principal of Lewisham College, is appointed CBE for her work in education.
A former soldier who spent 23 years sleeping rough in London has been recognised in the Queen's Birthday Honours list for helping the homeless.