The Lord of the Rings villain, also known for his role as Count Dracula in the popular Hammer Horror films, fought back tears as he was presented with the career accolade by Depp, who branded the 91 year old "a national treasure" and "a genuine artist", and revealed that working with Lee on Sleepy Hollow, Dark Shadows and his Charlie and the Chocolate Factory remake was "a childhood dream come true".
The veteran actor became emotional as he stepped up to the podium, telling Depp, "I didn't know you were going to be here. I must try and pull myself together."
He then returned the Hollywood hunk's compliments by referring to him as one of the few younger actors "who is truly a star".
Lee wasn't the only big winner at the London prizegiving - Pawel Pawlikowski was awarded Best Film for Holocaust drama Ida, while screenwriter Jonathan Asser was named Best British Newcomer for his work on prison film Starred Up.
The awards ceremony took place on the eve of the London Film Festival's final day - the 12-day event wrapped on Sunday (20Oct13) with the premiere of Tom Hanks' Saving Mr. Banks, which tells the back story of Mary Poppins.