Yes, in 1942 its screenwriters, Herman Mankiewicz and Orson Welles, won an Oscar for Best Writing of Original Screenplay. The film also received a number of other nominations, including Best Actor and Best Director, both for Orson Welles. You can see a full list of all its nominations here.

Although that might sound like a triumph, many critics and film people feel that one award was far too little for a movie that, ever since it was made in 1941, has consistently been voted the greatest ever made. In fact, last December that Oscar was auctioned for over $800,000.

It is sometimes thought that Citizen Kane was less well received than it should have been because it's based largely on the life of news tycoon Randolph Hurst, who had a powerful grip on the US media at that time and wasn't happy with the way he was portrayed in the film.