The night saw many stars take to the stage to honour Coppola, with De Niro calling him "an inspiration and one of my biggest influences".
Star Wars creator Lucas added, "(Coppola) taught me how to write. He taught me how to direct. He actually personified a whole era of the American film industry. He was our leader. He was our inspiration."
As he accepted the prize, Coppola told the crowd, "I have a great love of the original Hollywood tradition and admiration for the tradition of Irving Thalberg."
The honour wasn't Coppola's first Academy Award - he already has five trophies; four of them for his Godfather films.
Other stars honoured at the ceremony included historian Kevin Brownlow, director Jean-Luc Godard and actor Eli Wallach.
Kevin Spacey presented Brownlow with his trophy, while Clint Eastwood took to the stage to honour Wallach, branding him "a great performer and a great friend".