Three men, Red Pollard (Tobey Maguire), Charles S. Howard (Jeff Bridges), and Tom Smith (Chris Cooper) come together as the principal jockey, owner, and trainer of the championship horse Seabiscuit, rising from troubled times to achieve fame and success through their association with the horse.
In 1891, American Frank Hopkins (Viggo Mortensen) and his mustang, Hidalgo, are part of Buffalo Bill's Wild West show, where they are advertised as "the world's greatest distance horse and rider". Hopkins had been a famous distance rider, a cowboy, and a dispatch rider for the United States government; in the latter capacity he carried a message to the U.S. 7th Cavalry Regiment authorizing the Wounded Knee Massacre of Lakota Sioux.
During a thunderstorm, a traveling circus accidentally leaves behind a baby zebra. The foal is rescued by widower Nolan Walsh, a former Thoroughbred-racehorse trainer who retired when his wife, a jockey, died in a racing accident. Nolan takes the zebra home to his farm and leaves it under the care of his daughter Channing "Chan" Walsh, who names him "Stripes". Stripes befriends the other farmyard animals, including Saanen goat Franny and Shetland pony Tucker. One day, he becomes convinced that he is destined for the nearby racetrack, the Kentucky Open, after watching a race, not realizing that he is a zebra and is not qualified to race.
In 1969, Denver housewife and mother Penny Chenery (Diane Lane) agrees to take over her ailing father, Christopher Chenery's Meadow Stables in Doswell, Virginia, despite her lack of horse-racing knowledge. With the help of veteran trainer Lucien Laurin (Malkovich), Chenery navigates the male-dominated business, ultimately fostering the first Triple Crown winner in 25 years and one of the greatest racehorses of all time.
Alec Ramsey is aboard the steamer Drake off the coast of North Africa, where he sees a wild black stallion being forced into a makeshift stable and heavily restrained by ropes leading to his halter. Captivated by the horse, Alec later sneaks to the horse to feed him some sugar cubes, but he is caught by the horse's supposed owner, who tells him in Arabic to stay away from Shetan and shoves the boy away.
Alexandre Beck is a doctor who has slowly been putting his life back together after his wife Margot was murdered by a serial killer. Eight years on, Alex is doing well, until he finds himself implicated in a double homicide, which has plenty of evidence pointing to him as the killer – though he knows nothing of the crimes. The same day, Alex receives an email that appears to be from Margot, which includes a link to a surveillance video clip that features his late wife looking alive and well. The message warns Alex that they are both being watched. He struggles to stay one step ahead of the law, while henchmen intimidate Alex's friends into telling them whatever they might know about him – the henchmen eventually kill one of them, Charlotte. In the meantime, Alex's sister Anne persuades her well-off wife Hélène to hire a respected attorney, Élisabeth Feldman, to handle Alex's case.
In 1949, young cowboy John Grady Cole's maternal grandfather dies. John had grown up on his grandfather's ranch, but it was put up for sale when the old man died. His mother has no ties to it anymore, and would rather have the money. With no home, John asks his best friend Lacey Rawlins to leave his family ranch in San Angelo, Texas and join him to travel on horseback to cross the border 150 miles south, to seek work in Mexico. They encounter a peculiar 13-year-old boy named Jimmy Blevins on the trail to Mexico, whom they befriend but from whom they then separate. Later on they meet a young aristocrat's daughter, Alejandra Villarreal, with whom Cole falls in love.
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.
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.
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).