The James Bond legend has worked tirelessly for the United Nations Children's Fund since he was alerted to the cause by his late friend Audrey Hepburn in the 1980s.
Sir Roger was the star guest at a special reception in London on Thursday and was handed his prize by Unicef U.K.'s Vice-President Marc Bolland.
The actor told guests, "I am perhaps best known for my role as Bond, but my role as Goodwill Ambassador for Unicef is the one I am certainly most passionate about.
"One of the world's most glamorous and compassionate ladies recruited me to Unicef, Audrey Hepburn. Since then I've been moved by the incredible work the organisation does to save millions of children's lives and transform their futures.
"It is beyond doubt that it's the children and dedicated staff on the ground who deserve medals, but I am absolutely honoured and would like to thank Unicef for this truly humbling award."
The honour will now be known as The Roger Moore Lifetime Achievement Award.