Miracle on 34th Street

Kris Kringle (Edmund Gwenn) is indignant to find that the man (Percy Helton) assigned to play Santa in the annual Macy's Thanksgiving Day Parade is intoxicated. When he complains to event director Doris Walker (Maureen O'Hara), she persuades Kris to take his place. He does so well, he is hired to play Santa at Macy's flagship New York City store on 34th Street.

Ignoring instructions to steer parents to buy from Macy's, Kris directs one shopper (Thelma Ritter) to a competitor. Impressed, she tells Julian Shellhammer (Philip Tonge), head of the toy department, that she will become a loyal customer. Read more on Wikipedia.