Dear Mr. Prohack is a 1949 British comedy film directed by Thornton Freeland and starring Cecil Parker, Glynis Johns and Dirk Bogarde.

Arthur Prohack, a Treasury civil servant who is extremely frugal with the government's money, suddenly inherits £250,000 and is convinced to go on six months' sick leave.

His children Charles and Mary tap him for money for an investment scheme and a theatrical production respectively, whilst his wife Eve buys the family a far larger house, which she fills with an aviary and then aquariums.

Relieved he is about to be free of the troubles of his new fortune, Arthur retires to bed with a cold and has a fever dream inspired by Arthurian legends on the BBC Third Programme.

Arthur reconciles with Eve and makes plans to move back to their old house and help Oswald, Mary and Charles to more stable and healthy homes and jobs.