Based on actual events of the early twentieth century, the story concerns a grueling 700-mile cross-country horse race in 1906 and the way it affects the lives of its various participants.
The story begins with several odd occurrences at the farm where the Black, Alec (Kelly Reno), and his mother (Teri Garr) live. A suspicious barn fire is followed by the theft of the horse. From the point of view of Ishak (Ferdy Mayne), the sheik who took him, this is property retrieval; the horse was originally his, and the Black's name is Shetan. Although he learns that the horse is being returned to the sheik's kingdom in the Moroccan desert, Alec goes after the sheik, stowing away in a plane to Casablanca.
The film follows the adventures of Shetan, a young black Arabian colt. After a band of robbers separates a young Arabian girl named Neera (Biana Tamini) from her father, she finds herself alone in the desert. Before too long, a mysterious black colt comes to her rescue. The two quickly form a special bond, and the horse returns Neera to her grandfather. Once Neera is back home, the stallion disappears.
Phar Lap, known affectionately as "Bobby" by his strapper Tommy Woodcock (Burlinson), collapses and dies in Woodcock's arms, at Menlo Park in California, in 1932. The news is greeted with great sadness and anger in Australia. The remainder of the film is done as flashback.
In Reno, Nevada, Roslyn Tabor (Monroe) is a beautiful 30-year-old woman who has just gotten a quickie 6 week divorce from her inattentive husband Raymond (McCarthy). After leaving the Washoe County Courthouse, Roslyn's best local friend, Isabelle Steers, (Ritter) takes her to a bar at Harrah's Reno for drinks to let the reality of her divorce sink in. While there, they meet an aging cowboy named Gaylord 'Gay' Langland (Gable) and his tow truck driver friend Guido (Wallach). They invite Roslyn and Isabelle to Guido's place in the Nevada country to help her forget about the divorce, after Gay tells Roslyn that he is too divorced. They arrive at the un-finished house Guido had built for his wife, who had died several years earlier during childbirth. They drink and dance. Roslyn has too much to drink, so later Gay drives her home to Reno.
Sonora Webster is an orphan living with her aunt during the Great Depression. Sonora learns that because of the family's financial difficulties, her treasured horse Lightning will be sold and she will be placed in an orphanage. Instead, Sonora slips out of the house during the night.
Simpleton bachelor Fred Chaney (Goldthwait) inherits a buck-toothed horse named Don and one half of a stock brokerage firm from his dead mother. He discovers Don is a talking horse (who can also speak the language of several other animals) that belonged to his deceased father. His stepfather Walter Sawyer (Coleman) offers to buy out Chaney's share of the business for a paltry sum, but Chaney refuses. Instead Chaney returns Don to his talking-horse family in the countryside and claims his place as partner at the firm. Chaney takes over an office and begins working as a broker, much to the chagrin of Sawyer. Don the horse overhears a stock tip and calls Chaney, presumably using his teeth to dial the phone. Chaney acts on the investment advice and becomes wealthy overnight.
Sorrowful Jones (Matthau) is a gloomy, cantankerous bookie circa 1934, who is confronted by Carter, a gambler who cannot pay a $10 debt. He ultimately gives his 6-year-old daughter (Stimson) to Sorrowful's gangster-run gambling operation as a "marker" (collateral) for a bet. When he loses his bet and commits suicide, the gangsters are left with the "Kid" on their hands. Sorrowful's nervous assistant, Regret (Newhart), is concerned about the legalities of this, particularly the kidnapping statutes.
At their home, Dream Castle, the ponies are running and playing through flowery meadows and grassy green fields with their animal friends. Elsewhere, Baby Lickety-Split is practicing a new dance step, as Spike, a baby dragon, accompanies her rehearsal on the piano. Meanwhile, at the Volcano of Gloom, a wicked witch named Hydia is planning to ruin the ponies' festival, but her two incompetent daughters, Reeka and Draggle, are not up to her family's standards of wickedness, and she laments about it, before sending them off to ruin the festival. During the baby ponies' dance performance, Baby Lickety-Split attempts to add her own dance and ruins the whole performance. She is told off by everyone and runs away, followed by Spike, only to end up falling down a waterfall and trapped in a valley. Meanwhile, Reeka and Draggle try to ruin the ponies' festival by flooding the area, but thanks to the Sea Ponies, end up getting washed away in an overflowing waterfall.
National Velvet is the story of a 12-year-old girl, Velvet Brown (Elizabeth Taylor), who lives in the small town of Sewels in Sussex, England, who wins a spirited gelding in a raffle and decides to train him for the Grand National steeplechase. She is aided by a penniless young drifter named Mi (or Michael) Taylor (Mickey Rooney), who found Mrs. Brown's name and address among his late father's effects, but is unaware of what it was doing there. Hoping to gain some money from the association, Mi stays at the Browns' home, but Mrs. Brown is unwilling to allow Mi to trade on his father's good name and remains vague about how she knew him. Nevertheless she convinces her husband (Donald Crisp) to hire Mi over his better judgment, and Mi is brought into the home as a hired hand. It is revealed that Mi had been a jockey in Manchester, but his career ended in a collision which resulted in the death of another jockey. Since then Mi has not held a job, and he has come to hate horses. Velvet's horse is named "The Pie," short for "Pirate," the epithet given him by his owner due to the horse jumping clear of his paddock and wrecking things in the village. The man decides to be rid of the Pie, and offers him up in a raffle. Velvet wins The Pie, and on realizing the extent of the horses natural talent, she pleads with Mi to train the horse for the Grand National. He believes it a fools errand, not because of the horse, but because they have no real way to support the effort. He makes his case to Mrs. Brown, but she consents to Velvet's desire to train the horse. Velvet and Mi train the horse and enter him into the race. An experienced jockey is hired to ride him. The night before the race Velvet senses that the jockey hired to ride The Pie has no faith in him, and doesn't believe the horse can win. Velvet convinces Mi to fire the jockey, leaving them without a rider. That night Mi determines to overcome his fears and ride The Pie himself. Instead, he discovers that Velvet has slipped on the jockey's colors, and intends to ride the horse in the race herself. Aware of the dangers of such a race, Mi pleads with Velvet but is unable to dissuade her. As the race unfolds Velvet and The Pie avoid a number of falls, clear all the hurdles and win the race. Elated by their win, Velvet faints and falls off her mount at the finish. As she is revived the race doctor realizes she is not a young man, but a young woman. As such she and The Pie are disqualified, but Velvet knows The Pie proved himself. Velvet becomes a media sensation, declining an offer of £5,000 to travel to Hollywood with The Pie to be filmed. She ran the Pie at the Grand National because he deserved to have a chance. He wasn't an oddity to be stared at. In refusing the offer she states simply: "He wouldn't like being looked at." At the close of the film Mi takes his leave, and Mrs. Brown gives Velvet permission to reveal to him the nature of her relationship with his father. Velvet rides off to catch up with Mi and tell him that his father had been Mrs. Brown's coach when she won the prize as the first woman to swim the English Channel, many years before.
Jay Trotter drives a cab. His friend Looney, also a cab driver, has a secret microphone in his taxi to record his passengers' conversations. Looney has a tape of two men talking about a horse race and how one of the horses, due to some unethical practice by its owner, is a sure thing to win big. Jay goes to the track to place a bet—despite the fact that the day before, he told his wife Pam that he would quit betting and be home to "start their marriage over" at noon. In the restroom of the bar next door, he prays to God, "Just one day, that's all I'm asking for, one day, I'm due." A man exiting the bathrooms says "Ya? So's Jesus. Let it ride." Jay promptly places a $50 bet. The horse wins in a photo finish and pays $28.40 to win (earning him $710).
Black Beauty (voiced by Alan Cumming; played by Docs Keepin Time) narrates his story. He is born on a farm in the English countryside and remains by his mother's side until he is sent to Birtwick Park to serve Squire Gordon and his family.
New York City in the 1920s is where gambler "Honey Talk" Nelson (Dean Martin) crosses paths with bookie "Jumbo" Schneider (Sheldon Leonard). Nelson has two choices, cement shoes or "fixing" a horse race in Maryland. Naturally, Nelson heads to Maryland with his cousin Virgil Yokum (Jerry Lewis) tagging along.
Madison Avenue advertising executive Fred Bolton, a Lakeville, Connecticut widower living beyond his means, is beset by two major problems. First, his boss at Tomes Advertising Agency has instructed him to come up with an original campaign – in 24 hours – to promote star client Allied Drug & Food's over-the-counter indigestion medication, "Aspercel." Allied's Chairman of the Board, Tom Dugan, wants a "jet-set" appeal campaign that will "give sour stomachs class and dignity."