Ice Age: Dawn of the Dinosaurs is a 2009 American animated adventure comedy film produced by Blue Sky Studios and distributed by 20th Century Fox. It is the sequel to Ice Age: The Meltdown (2006) and the third installment in the Ice Age film series. It was directed by Carlos Saldanha and co-directed by Mike Thurmeier, from a screenplay written by Michael Berg, Peter Ackerman, Mike Reiss, and Yoni Brenner, based on a story conceived by Jason Carter Eaton. Ray Romano, John Leguizamo, Denis Leary, and Chris Wedge reprise their roles from the first two films and Seann William Scott, Josh Peck, and Queen Latifah reprise their roles from The Meltdown, with Simon Pegg joining them in the role of a weasel named Buck. In the film, while Manny and Ellie are preparing for their baby, Sid the Sloth is kidnapped by a female Tyrannosaurus after stealing her eggs, leading the rest of the herd to rescue him in a tropical lost world inhabited by dinosaurs underneath the ice.

The film was released on July 1, 2009, becoming the first Ice Age film and the first 20th Century Fox film to be released in 3D. It received mixed reviews from critics, and has grossed $886.7 million worldwide, making it the third-highest-grossing film of 2009, the highest-grossing animated film of 2009, the highest-grossing Ice Age film and the highest-grossing film from Blue Sky Studios. Two sequels, Ice Age: Continental Drift and Ice Age: Collision Course, were released in 2012 and 2016, respectively.

Ellie is pregnant, making Manny desperate to make life safe for both her and their upcoming child, not wanting them to meet the same fate as his previous wife and child. However, Manny's desperation alienates Diego, who contemplates leaving the herd, feeling like he's losing his hunter instincts. Sid on the other hand, becomes anxious of being abandoned which leads him to discover three apparently abandoned eggs underground that he decides to adopt. Manny tells Sid to put the eggs back, but Sid ignores him and looks after them, hatching into baby Tyrannosaurus the next morning. Meanwhile, Scrat becomes infatuated with a flying saber-tooth squirrel named Scratte, though she only wants his acorn.

Although Sid tries his best to raise the dinosaurs, their rambunctious behavior scares away the younger animals and destroys the playground Manny built for his child, angering Manny. The mother Tyrannosaurus whose eggs Sid took arrives. When Sid refuses to return her children, she carries both Sid and her children underground. The two mammoths and possums follow them, discovering that the icy cave leads to a vast subterranean lost world populated by dinosaurs. After escaping a territorial dinosaur and reuniting with Diego, they are surrounded by more dinosaurs, but are saved by a one-eyed weasel named Buck.

Buck reveals he has lived in the jungle for a long time, and is trying to hunt down Rudy, a monstrous albino Baryonyx who took Buck's missing eye. He agrees to lead the group through the jungle to Lava Falls, where the mother dinosaur is taking Sid and her babies. Meanwhile, the mother Tyrannosaurus tries to get rid of Sid, but slowly grows attached to him. The next morning however, Sid is separated and chased by Rudy. Sid escapes, but gets stranded on a loose rock floating on a river of lava, heading to plummet over the falls.

Nearing lava falls, Ellie goes into labor and a pack of Guanlong causes a rock slide that separates her from the rest. Buck commands Manny and Diego stay behind to protect Ellie while he and the possums rescue Sid. Diego regains his edge from defeating the Guanlong while also supporting Ellie emotionally as she gives birth. Manny slows down the rest as he makes his way up to her. Buck, Crash and Eddie ride a Harpactognathus to lava falls, but a pack of Quetzalcoatlus follow, preying on the possums and forcing them to detour through a canyon. They defeat the Quetzalcoatlus, and return to Lava falls, just in time to rescue Sid. Back at the plates, the remaining Guanlong are defeated with Manny reaching Ellie just in time to see his newborn daughter, agreeing to name the baby "Peaches". Sid is happy to reunite with his friends, but is sad that he never had a chance to say goodbye to the Tyrannosaurus.

Before leaving the jungle, they are ambushed by Rudy but the herd is eventually saved by the mother Tyrannosaurus, who charges at Rudy and knocks him off a cliff. Sid then says goodbye to the dinosaurs, and Buck, now without a purpose in life since Rudy is gone, decides to join the herd and live on the surface. However, a distant roar tells him that Rudy is still alive. Changing his mind, he sends the herd home and blocks off the path to the lost world. Manny and Ellie welcome Peaches into their frozen world, and Diego decides to remain with the herd, while Buck stays underground, trying to tame Rudy.

Meanwhile, Scrat and Scratte decide to live in the jungle together, but Scratte suddenly becomes bossy, making Scrat choose the acorn over her. Scratte catches him and takes away the acorn, causing a fight. Scrat is accidentally launched back to the surface, while both the acorn and Scratte are trapped in the dinosaur world.

• Ray Romano as Manny, a woolly mammoth and the leader of The Herd. He is also Ellie's husband, Sid and Diego's best friend and Peaches' father.
• John Leguizamo as Sid, a ground sloth and the founder of The Herd. He is also Manny and Diego's best friend and the adoptive father of the three baby dinos.
• Denis Leary as Diego, a smilodon and a member of The Herd and Manny and Sid's best friend.
• Simon Pegg as Buck, a dinosaur-hunting weasel who joins The Herd.
• Queen Latifah as Ellie, a female woolly mammoth, Manny's wife, Peaches' mother and Crash and Eddie's foster sister.
• Seann William Scott as Crash, an opossum, Eddie's biological brother and Ellie's foster brother.
• Josh Peck as Eddie, an opossum, Crash's biological brother and Ellie's foster brother.
• Chris Wedge as Scrat, a saber-toothed squirrel.
• Karen Disher as Scratte, a female saber-toothed flying squirrel, and Scrat's love interest and rival
• Frank Welker as Momma, Rudy and Additional Dinosaurs
• Bill Hader as Gazelle
• Jane Lynch as Diatryma Mom
• Kristen Wiig as Pudgy Beaver Mom
• Carlos Saldanha as Dinosaur Babies / Flightless Bird
• Eunice Cho as Madison (Diatryma Girl)
• Maile Flanagan as Aardvark Mom
• Christian Pikes as Little Johnny, an aardvark
• Clea Lewis as Start Mom
• Randy Thom as Additional Dinosaurs
• Devika Parikh (additional voices)

Blue Sky decided to do "more of a what-if adventure" in the third Ice Age installment, "like finding the giant ape in King Kong or a Shangri-la in the middle of snow," and added the dinosaurs to the story. Character designer Peter de Sève welcomed the new plot addition, since he could not think of any other giant mammal to put into the story. The "lost world" approach led to colorful dinosaurs, because "the dinosaurs didn't have to be just brown, and you can take liberties because no one knows what color they were", according to de Sève. Rudy's design was inspired by the Baryonyx because of his crocodile-like look, which de Sève considered even more menacing than the T. rex.

Ice Age: Dawn of the Dinosaurs held special screenings on Father's Day, June 21, 2009, in 330 theaters across the United States, exclusively in 3-D. That day was chosen due to the film featuring a theme of fatherhood. Widely, it was released on July 1, 2009.

The film was released in RealD 3D where available. This sparked some controversy when Fox announced that it would no longer pay to supply 3-D glasses to theaters, leading to a number of exhibitors threatening to show the film in only standard 2-D projection.

Ice Age: Dawn of the Dinosaurs was released on standard DVD and high-definition Blu-ray Disc in North America on October 27, 2009. Two versions of the DVD were released: a single-disc DVD, and a "Scrat Pack" double DVD pack with three Scrat games. The 3-disc Blu-ray combo pack included a Blu-ray, the single-disc DVD, and a Digital Copy, as well as an Ice Age digital story-book maker, commentary by director Carlos Saldanha, deleted scenes, making-of featurettes, the two Scrat shorts: Gone Nutty and No Time for Nuts (that each originally came on home video for both the first and second films), and a how-to-draw Scrat tutorial with the filmmakers.

A Blu-ray 3D version of the film was exclusively available with purchase of select Panasonic's television sets between May 16 and July 10, 2010, and was widely released on August 30, 2010. On September 21, 2010, a 3-D DVD was released as a two-disc set, with the first disc being the TrioScopics 3-D (green-magenta anaglyph) version and the second disc being the 2-D version.

The film earned $196.6 million in North America and $690.1 million in other territories for a worldwide total of $886.7 million against a budget of $90 million. Worldwide, it is the third-highest-grossing film of 2009, the highest-grossing animated film of 2009, the highest-grossing Ice Age film, the 14th-highest-grossing animated film of all time. It is also the highest-grossing animated film of 2009 worldwide. Ice Age: Dawn of the Dinosaurs also surpassed Finding Nemo to have the highest international gross for an animated film. The film grossed $218.4 million during the opening weekend, and was the highest-grossing opening for an animated film. It would hold that record for less than a decade until it was surpassed by Incredibles 2 in 2018.

The film made $13.8 million on its opening day in 4,099 theaters. It reached $41.7 million on its first weekend at second place behind Transformers: Revenge of the Fallen, marking the lowest-grossing first weekend for the franchise, although it had a Wednesday release and therefore burned off attendance until the weekend. The film became Fox's third-largest 2009 release in North America, behind Avatar and Alvin and the Chipmunks: The Squeakquel. It is the third-highest-grossing animated film of 2009. It barely surpassed its predecessor, Ice Age: The Meltdown which earned $195.3 million three years before, to become the highest-grossing film in the franchise, but it was behind the two first Ice Age films in estimated attendance.

On its opening weekend it earned $151.7 million, which is the biggest opening for an animated feature. Its highest-grossing market after North America was Germany ($82.2 million), followed by France and the Maghreb region ($69.2 million), and the UK, Ireland and Malta ($56.9 million). It was the highest-grossing animated film of the year in all major countries, except Spain and Australia.

On Rotten Tomatoes, the film has an approval rating of 46% based on 165 reviews and an average rating of 5.4/10. The site's critical consensus reads, "Ice Age: Dawn of the Dinosaurs boasts some excellent animation -- in particular, the dinosaurs are wonderfully realized -- but its story is tired and monotonous." On Metacritic, the film has a score of 50 out of 100 based on 25 critics, indicating "mixed or average reviews". Audiences polled by CinemaScore gave the film an average grade of "A−" on an A+ to F scale.

Roger Ebert gave the film three and a half stars out of four claiming that "Ice Age: Dawn of the Dinosaurs is the best of the three films about our friends in the inter-species herd of plucky prehistoric heroes. And it involves some of the best use of 3-D I've seen in an animated feature." Keith Phipps of The A.V. Club graded the film a C+ claiming the sequel "throws its commitment to the era away with movie number three, a ploy sure to anger Ice Age purists everywhere." Carrie Rickey of The Philadelphia Inquirer enjoyed the "film's animation art is Seuss-imaginative", but panned "the flatness of the story and indifferent voicework all the more obvious." James Dyer of Empire gave the film three out of five stars, calling it a "pacey, enjoyable yarn for the most part" and praise Pegg's performance, stating "Long-in-the-tooth characters detract from the usual high-spirited fun and frolics."

Phillip French of The Guardian was critical of the film's crude humor and felt that "most adults will find it...too long". Also writing for The Guardian, Ben Child wrote that he found the film predictable, and despite praising the Scrat subplot, felt "there were precious few laughs and no real feeling that anyone aside from the animation team was really pushing themselves. You can pretty much tell exactly what's going to happen, and what each character is about to say...I actually found myself almost drifting off at one point." Richard Propes offered a negative review, considering the film to be the worst in the series and though in praise of the animation, was critical of the characters and storyline, feeling it "never come to life and never become involving." TheScoreCard gave the film 3 out of 10 stars and wrote "... the voice talents aren’t as popular as they were originally in 2002...the moments when it can use new character Buck or seasoned silent film star Scrat to keep audiences interested. As zany as Simon Pegg’s voicing is of the wacko weasel, and as timeless as Scrat’s existence may be, no two characters alone can save this threequel from being a weak moment for animated storytelling. They certainly can’t make another Ice Age movie entirely worth it".

Some criticism has been directed at its ending to the Scrat sub plot in which Scrat loses both the acorn and Scratte after a fight. Drew Friday criticises the "played for laughs but comes across as mean-spirted, 'Scrat abandons his desires for love, and for a time he is happy and unpunished. But the pull of the acorn proves too much for him to resist, and he turns his back on love. And he is punished", arguing that it is made more frustrating by the fact that Scratte never made another appearance in the series: "Cut the final few minutes from 'Dawn of the dinosaurs' and imagine what a finale that would have been!"

The film was nominated in two categories at the 8th Visual Effects Society Awards, for "Outstanding Animation in an Animated Feature Motion Picture" and "Outstanding Animated Character in an Animated Feature Motion Picture."

Ice Age: Dawn of the Dinosaurs - The 4-D Experience is a 14-minute 4-D film shown at various 4-D theaters over the world. It retells the condensed story of Ice Age: Dawn of the Dinosaurs with the help of 3-D projection and sensory effects, including moving seats, wind, mist, snow and scents. Produced by SimEx-Iwerks, The 4-D Experience premiered in May 2012, at the San Diego Zoo 4-D Theater. Since June 2012, it is being shown at the Roxy Theatre, at the Warner Bros. Movie World in Australia, and since July 2012, at the Shedd Aquarium's Phelps Auditorium in Chicago.

A tie-in video game was published by Activision. The game allows players to play as one of the film's characters, discovering the underground world of dinosaurs and solving puzzles through more than 15 levels.

A fourth film, Ice Age: Continental Drift, was released in 3D on July 13, 2012. A fifth film, Ice Age: Collision Course, was released in 3D on July 22, 2016.

• List of animated feature-length films
• List of computer-animated films
• List of films featuring dinosaurs

• Official website at the Wayback Machine (archived June 27, 2009)
• Ice Age: Dawn of the Dinosaurs at Rotten Tomatoes
• Ice Age: Dawn of the Dinosaurs at IMDb