Gill Hicks, who lost both of her legs in the terrorist attack, is walking from King's Cross to Tavistock Square alongside the religious leaders in a "moment of quiet remembrance" to pay tribute to the 52 people who died.
She is carrying a floral tribute reading "Together".
Joining her is Imam Qari Asim, of Leeds' largest mosque Makkah Masjid, Revd Bertrand Olivier, vicar of All-Hallows-by-the-Tower in the City of London, and Rabbi Laura Janner-Klausner, from Movement for Reform Judaism.
The procession is calling on people from the city of all faiths and none to unite to "walk together" on the 7/7 anniversary by finishing their morning bus or Underground commute one stop early and walking the last few minutes.
Gill Hicks said: "My life and those around me changed forever on July 7 2005.
"I believe in the power and brilliance of humanity - my life was saved by strangers, people who never gave up, people who risked their own lives to save mine.
"To them, I was a precious human life - my rescue wasn't dependent on my faith, my colour, my gender or wealth.
"Walking Together allows us the time and space to talk, to share and to know the 'other'. Our unity can offer the strength to not only deter anyone from following the path of violent extremism, but to also build a sustainable peace."
Ms Janner-Klausner said: "The attacks on London were an attack on all of us - black and white, rich and poor, different faiths and none.
"That's why we've decided to join hands and call on people all over Britain to walk side by side in a moment of remembrance and of unity on 7/7.
"That would be a very powerful statement about who we are as a country."
Walking together and talking together. In memory of 7/7. Just leaving Kings X. #walktogether @QariAsim pic.twitter.com/7Q1JHdegln
— Laura JannerKlausner (@LauraJanklaus) July 6, 2015Listen to Premier's Hannah Tooley speak to Revd Bertrand Olivier who is walking, here:
