Ted Wiggins, an idealistic 13-year-old boy, lives in "ThneedVille", a walled city that, aside from the citizens, is completely artificial. He sets out to find the one thing that will win him the affection of Audrey, the girl of his dreams, who wishes to see a real tree. Ted's energetic grandmother suggests he speak with the Once-ler on the matter, and he discovers that their city has been closed off from the outside world, which is a contaminated and empty wasteland. The Once-ler agrees to tell Ted about the trees if he listens to his story over multiple visits. Ted agrees, even after the mayor of Thneed-Ville, Mr. O'Hare, the greedy proprietor of a bottled oxygen company, confronts the boy and pressures him to stay in town.
Over the visits, the Once-ler recounts the story of how he met the Lorax, a grumpy yet charming creature who serves as guardian of the land he arrived in and actively resists his logging until the Once-ler agrees to desist. When the young businessman introduces a revolutionary invention from the native Truffula Tree's tufts, the thneed, it eventually becomes a major success and the Once-ler's family is brought in to participate in the business. Keeping his promise at first, Once-ler continues thneed production by harvesting the tufts themselves in a sustainable manner. Unfortunately, his greedy and lazy relatives convinced him to resume logging as a more efficient gathering method, and the destruction of the forest spirals into a mass overproduction. Flush with wealth, the Once-ler rationalized his short sighted greed into an arrogant self-righteousness that even co-opts the helpless protests of the Lorax for his own ends. As a result, he completely depleted the forest while making the region uninhabitable with his business' pollution. With that, the Once-ler was left ruined and abandoned by his family and became a recluse with the creation and isolation of Ted's town that came under Mr. O'Hare's control. Eventually, the Lorax sends the wildlife (and the Once-ler's horse) away before departing himself, leaving a stonecut word, "Unless."
At the end of the story, Ted is inspired by the Once-ler's gift of the last Truffula Seed to plant it to remind his town of the importance of nature. Unfortunately, O'Hare is determined to not have trees undercut his business and takes heavy handed steps such as destroying Audrey's nature paintings and forcibly searching Ted's room for the seed. Ted is undeterred and enlists his family and Audrey to help plant the seed. O'Hare and his employees pursue the dissidents until they manage to elude him and reach the town center. Unfortunately, their attempt to plant the seed is interrupted by O'Hare who rallies the population to stop them. To convince them otherwise, Ted takes an earthmover and rams down a section of the city wall to reveal the environmental destruction outside. Horrified at the sight and inspired by Ted's conviction, the crowd defies O'Hare and the seed is planted.
At the Once-ler's house, the Truffula forest is beginning to recover with the Once-ler's participation and the Lorax returns, pleased that his friend is undoing the harm he caused. The Once-ler, overcome with joy that his friend has returned, embraces him as they walk towards his house.
- Zac Efron as Ted
- Danny DeVito as The Lorax
- Taylor Swift as Audrey
- Ed Helms as The Once-ler
- Rob Riggle as O'Hare
- Betty White as Grammy Norma
Reception and Box Office
As of March 17, 2012, the film had received a score of 58% Fresh at the review compilation site Rotten Tomatoes, a majority of positive reviews, but just shy of a "Fresh" rating, which requires 60% or greater. The site's consensus of film critics' opinions stated that "Dr Seuss' The Lorax is cute and funny enough but the moral simplicity of the book gets lost with the zany Hollywood production values. Overall audience reviews were much more favorable, rating the film with a CinemaScore grade of A. As such, the film grossed the bigggest U.S. domestic opening weekend to date of 2012 with a total of $70.2 million, enough to make up its production cost in the opening weekend.  In its second weekend The Lorax brought in $38.8 million domestically, pushing the domestic take over the $100 million mark.
- The characters of Ted and Audrey are named after Dr. Seuss (whose real name was Theodor Seuss Geisel) and his second wife Audrey Geisel.
- The Lorax was the first film based on a Dr. Seuss property to be released in 3D, which is jokingly referred to promotionally as "IMAX Tree-D."
- The song used in the theatrical trailer for The Lorax is "Light and Day" by The Polyphonic Spree. Other songs include "Campus" by Vampire Weekend; and "Quest for Glory" by Q-Factory.
- In conjunction with the premiere of The Lorax, IHOP (International House of Pancakes) is offering a set of Dr. Seuss themed breakfast menu items. It is also offering a contest and a challenge to plant 3 million trees, with a bookmark with tree seed paper being given free to kids 3 to 12 while supplies last. The official website can be found here.
- The film itself, there is a variant of this logo in which the text is already formed, and two minions from Despicable Me are seen cutting a Truffula Tree with a chainsaw. Lou the Bar-ba-loot then lands on one of them, eating some truffula berries. The other minion slowly backs away nervously.
- There's a cameo of a minion from Despicable Me, when Ted's grandma was telling him to get supplies for the Once-ler.
- This is the third Dr. Seuss' film to receive a PG rating, after The Cat In The Hat, and the first animated film to receive that rating.
- In the book, the Lorax came out of the treestump as soon as the Once-ler chopped it down, but in this film version, the Once-ler didn't see any of that magical event, which didn't take place until after one of the humming-fish knocked on it. Most likely, this better accutates an old lumberjack superstition that one must knock on the wood of a tree before chopping it down as to ask permition from the nature spirit inside to do so and to promice to plant a seed in its place. Since the Once-ler was naïve in youth to the rules of respecting nature, the "knock on wood" concept makes sense for summoning the Lorax.
Soon after the film's release, it was reported that Universal Studios are considering a sequel to the film with the possibility of Taylor Swift and Zac Efron reprising their roles. Since then there has been no further announcements.