This was among the last MGM films shot on the studio's renowned back lot, of which there were actually six distinct satellite parcels of land west and south of the main lot, or Lot 1. Lot 2, the last of them to serve as a working back lot, was in use until late 1978. Development for residential housing on Lots 3-6 began the year "That's Entertainment!" filmed its new material with the studio's stars strolling the various standing sets, which had been allowed to deteriorate for well over a decade before their demolition. This is particularly noticeable in the train station set where Fred Astaire gives his introduction, and Bing Crosby refers to the English Lake area as looking rather "scruffy". On the other hand, the entire purpose of the film is nostalgia, and the use of the 'scruffy' facade, clearly aged and unused, helps to set the tone as one of a brief return to the glamor of the past, even though it was all make-believe.
Norma Shearer made an agitated phone call to MGM senior executive Paul Rosenfeld, insisting that her reaction shots to Clark Gable's 'Puttin' on the Ritz' (from Idiot's Delight (1939)) be deleted. Unfortunately, it was too late to make any changes and the shots remained in the film. Shearer explained to Rosenfeld in a letter, "I am presented as no more than an extra without screen credit while others who are dancers and singers perform triumphantly as stars of this production." When Rosenfeld offered to arrange a screening for Shearer, she declined saying, "I would be devastated to see myself as such an insignificant part of the whole...It is a little too late to do anything now except to express to you my wounded pride."
The movie's dedication: "Over the years, under the leadership of Louis B. Mayer and others, Metro-Goldwyn-Mayer has produced a series of musical films whose success and artistic merit remain unsurpassed in motion picture history. There were literally thousands of people... artists, craftsmen and technicians... who poured their talents into the creation of the great MGM musicals. This film is dedicated to them."
Was originally advertised with the tagline: "Boy, do we need it now!" This slogan attracted moviegoers to the film, seeing it as an escape from the gritty "New Hollywood" style of filmmaking, to say nothing of real life turmoils such as the Vietnam War and the Watergate Scandal.
An earlier poster professes that the "Good Morning" number from Singin' in the Rain (1952) was originally inserted in Debbie Reynolds's hosting segment, but was cut before release - and later placed in That's Entertainment, Part II (1976). This much is true; it was ultimately replaced with "Make 'Em Laugh." But the segment with Reynolds' narration is definitely NOT included in the promotional short Just One More Time (1974).