Mr Holmes, deputy chief executive of the Diana Award, said: “It is a huge honour to receive this OBE.
“It was particularly poignant to be awarded by The Prince of Wales who I’ve worked with at The Diana Award, set up in memory of his mother, for many years.”
The ambassadors programme has a network of trained young people dedicated to preventing all types of bullying particularly in schools, the charity said.
Chief executive Dr Tessy Ojo said: “Alex’s pioneering leadership and passionate commitment to young people has been immense.
“He is an inspiration to so many young people at The Diana Award who have been impacted by his work.”
The Diana Award was set up in memory of Diana, Princess of Wales, 25 years ago, as she believed young people have the power to change the world.