"Screen Director's Playhouse" broadcast a 30 minute radio adaptation of the movie on May 8, 1949 with James Stewart reprising his film role.

"Smith Wins Nomination", the newspaper headline, has nothing to do with Mr. Smith Goes to Washington. It refers instead to Governor Alfred E. Smith of New York, the "Happy Warrior" who ran for President as a Democrat in 1928. Republican Herbert Hoover defeated Smith.

Jean Arthur was Frank Capra's first choice for the part of Mary. However, she declined the role since she was already committed to a Broadway play.

Ginger Rogers was offered the role of Mary, but turned it down.

Frank Capra often said that this was his favorite of all his films.

Frank Capra strove to make scenes as real as he could for actors. Thus the first kiss between Stewart and Reed was shot at the same time as the other end of the phone conversation, with Sam Wainwright (Frank Albertson) on a different set (Wainwright's New York office) at RKO's Pathe studio.

Frank Capra: [Jimmy the Raven] this bird appeared in all of Frank Capra's movies.

James Stewart and Donna Reed reprised their roles in 1947 on radio, first on "The Lux Radio Theatre" and then on "Camel Screen Guild Theatre." In the Lux version, instead of putting Zuzu's petals in his pocket, George has a bell that Zuzu likes to play with. The "Lux" version aired in March; the "Screen Guild" version aired December 29th.

James Stewart cited George Bailey as being his favorite character. The part was originally developed at another studio with Cary Grant earmarked for the role. When Frank Capra inherited the project, he rewrote it to suit Stewart.

James Stewart repeated his role in a one-hour radio version for NBC Radio Theater in 1949.

James Stewart said that of all the films he made, this was his favorite.

James Stewart was nervous about the phone scene kiss because it was his first screen kiss since his return to Hollywood after the war. Under Frank Capra's watchful eye, Stewart filmed the scene in only one unrehearsed take, and it worked so well that part of the embrace was cut because it was too passionate to pass the censors.

James Stewart's performance as George Bailey is ranked #8 on Premiere Magazine's 100 Greatest Performances of All Time (2006).

Dalton Trumbo, Dorothy Parker, and Clifford Odets all did uncredited work on the script.

Laraine Day was offered the role of Mary but had to decline because she was already busy working on 'The Locket'.

Donna Reed's first starring role.

Lionel Barrymore convinced James Stewart to take the role of George, despite his feeling that he was not up to it so soon after World War II.

Vincent Price was considered for the part of Mr. Potter.

350,000 feet of film were used.

According to an interview with Karolyn Grimes, the actress who played Zuzu, the name Zuzu comes from Zu Zu Ginger Snaps. George makes reference to this near the end of the movie when he says to Zu Zu at the top of the stairs, "Zuzu my little Ginger Snap!"