In May 1944, 5 years since the declaration of World War II, three Royal Homing Pigeon Service war pigeons are flying across the English Channel with the White Cliffs of Dover in sight, carrying vital messages to Great Britain. Despite the poor weather conditions the pigeons have nearly reached their destination, however, they are suddenly ambushed and attacked by a German enemy falcon called General Von Talon, two of the pigeons are instantly killed, yet the third is taken as a prisoner of war.
Elsewhere a small wood pigeon named Valiant is watching an Allied forces propaganda film in his local bar (an overturned rowing boat) in West Nestington. Wing Commander Gutsy, a war hero flies into the bar, informing everyone that signups are scheduled the next day in Trafalgar Square, London. In General Von Talon's lair Mercury, the captured prisoner of war resists interrogation by his captors. Valiant flies off to London, bidding his mother and Felix, the local barman, goodbye. In London, Valiant meets a filthy pigeon named Bugsy, who is wanted by two thugs. In order to escape the wrath of the thugs, he signs up with Valiant.
The recruits, Valiant, Bugsy, Lofty, an intellectual red pigeon, and Toughwood and Tailfeather, two strong but dim-witted twin brothers, form Royal Homing Pigeon Service Squad F, and are sent to a recruit training facility. Under the command of Sergeant, who declares that he will toughen them up for the RHPS, the training begins. Meanwhile, Von Talon and his henchmen try numerous attempt to discover the message's departure location. However Mercury refuses to tell, despite the tortures inflicted upon him, such as irritating him with yodelling music and injecting him with truth serum, before Mercury accidentally reveals the location: Saint-Pierre.
Throughout the training, Valiant develops a crush on Victoria, the camp's nursing dove. Eventually, Gusty arrives and tells the Sergeant that the recruits need to leave the next morning, despite their training being vastly incomplete. Bugsy, however, decides not to go on the "highly dangerous" mission and flees the camp that night. The next morning, Valiant and the others prepare to leave and start to board the plane headed for France, not before Bugsy shows up at the last second. The journey becomes extremely perilous, as it is caught in the midst of dogfight. Their plane sustains heavy damage and the pigeons soon have to bale out, in boxes equipped with parachutes. The pigeons are dropped from the plane, however a technical malfunction causes Gutsy's box to fail to deploy. The plane goes down in an inferno of flames, presumably killing Gutsy in the resulting explosion.
In France, the pigeons meet Charles de Girl and Rollo, two mice from the French Resistance, Mouse Division, the latter being an expert saboteur who lead them to Saint-Pierre, where they receive the message they have been ordered to deliver. They soon come under attack by Von Talon's henchmen, resulting in Bugsy and the message being captured. Von Talon takes the message from Bugsy and decides to cage him up and eat him later. Valiant and the troops follow Bugsy to the falcon's bunker, where they discover that Gutsy has survived the plane crash. Valiant takes advantage of his small size and sneaks into the bunker through the gun barrel, retrieves the message, and frees Bugsy and Mercury. Unfortunately, the falcons are alert and give chase. As Gutsy and the others fend off Von Talon's henchmen, Valiant flies to London to deliver the message, followed closely by Von Talon.
After a climactic chase by the falcon, Valiant hides in the cottage where he lives, where he is attacked by Von Talon again. With the help of his mother and Felix, Valiant finally defeats the villain by getting a giant hook caught on his medals, leaving him to be beaten senseless by the water wheel. Valiant delivers the message, and is rewarded with a Dickin Medal. After receiving the Dickin Medal, Squad F returns to the local bar in West Nestington, where Valiant reunites with Victoria.
- Ewan McGregor as Valiant, the protagonist of the film.
- Ricky Gervais as Bugsy, Valiant's friend in the Royal Homing Pigeon Service.
- Pip Torrens as Lofty Thaddeus Worthington, Valiant's friend in the Royal Homing Pigeon Service.
- Dan Roberts and Brian Lonsdale as Toughwood and Tailfeather, Brothers and Valiant's friends in the Royal Homing Pigeon Service.
- John Cleese as Mercury
- Olivia Williams as Nurse Victoria
- John Hurt as Felix
- Annette Badland as Elsa
- Jim Broadbent as Sergeant Monty
- Hugh Laurie as Wing Commander Gutsy
- Tim Curry as General Von Talon, the antagonist of the film.
- Rik Mayall and Michael Schlingmann as Cufflingk and Underlingk
- Sharon Horgan as Charles De Girl
- Buckley Collum as Rollo
- Sean Samuels as Jacques
179 modellers, animators, shaders, texturers began work on Valiant at Ealing Studios, west London. Valiant was the first CGI film to be made in Britain. John H. Williams of Vanguard Animation "we knew a lot of European animators who had worked at Pixar, Disney and DreamWorks, and were interested in going back to Europe. We thought it would be important to be the first company to produce a CGI feature fully made in Europe with a major studio attached." Williams also explained the attraction to making the film in Britain, saying "It would have been $3 million cheaper to make in LA but we had $10-12 million in tax and co-production money that we were able to attract because we made it here." Additionally, the bonus of locating to Britain was that the UK Film Council offered Valiant a record-breaking £2.6 million grant. Valiant's budget of $35,000,000 is considerably low in comparison to other CGI productions, with films which Williams had previously worked on, such as Shrek 2 having a budget of $150,000,000.
The animals were clothed under Chapman's orders to create a more distinctive look for each character. The film, on a tight budget and with a relatively small group of animators, was created in 106 weeks, in what The Times described as "a piece of guerrilla film-making" in comparison to the other CGI animated films created by major studios. At least 5 computer animators worked together for every scene of the 76 minute film, working on effects such as colour, movement and shading. As a result of the low amount of animators, some critics called the film's animation "amateurish-looking". However, other reviewers stated that the film was "nicely animated".
Tom Jacomb, line producer for Vanguard Animation stated that the biggest difficulties whilst making the film was the detail required for the bird's feathers. He stated that "most — no, all — our problems were feathers", and described them as a "misery in computer animation". Director Gary Chapman insisted that each bird must look distinctive, and as a result, the pigeons came in various colours, including beige, blue, yellow, red and grey. He also requested that each bird be dressed in clothing, and clothing accessories appear throughout the film on characters, usually hats, belts, and military medals and, in the case of the villainous Von Talon, a black leather cape. However, before Valiant, Bugsy, Lofty Thaddeus Worthington, Tailfeather, Toughwood complete their military training, they appear entirely clothes-free, equipped with no military regalia.
Valiant received a 30% "rotten" rating on Rotten Tomatoes based on 109 reviews with an average rating of 5/10. The film did business of $19,478,106 in the U.S. and $42,268,782 internationally. This gives it a worldwide total of $61,746,888, which is considered successful, but low by CGI film standards. The film held the record for lowest box office of a CGI animated film, until its record was later beaten in 2006 by Doogal, the re-dubbed version of The Magic Roundabout. As of 2015, the film is the lowest box office of a Disney Animated Film.
The musical score was composed by George Fenton and mostly performed by the Royal Philharmonic Orchestra. The orchestral music is in keeping with the military theme of the film, especially in the case of tracks such as "March of the R.H.P.S.", which was performed by The Central Band of the Royal Air Force. The tracks were recorded at AIR Recording Studios and at Angel Recording Studios in London and at Right Track Studios, New York. The only track not composed by Fenton, and the only track featured on the soundtrack with vocals, is "Shoo Shoo Baby", sang by R&B girl group Mis-Teeq. "Shoo Shoo Baby" was originally sang by the Andrews Sisters, a popular American wartime group. Although "Shoo Shoo Baby" was the only track on the album containing lyrics, it was not the only lyrical track used in the film; "Non, je ne regrette rien" by Édith Piaf is played in one scene in the film, despite it being recorded in 1960, 16 years after 1944, when the film was set.