Steve Carell as Gru, the world's former #1 super-villain. He intends to shrink and steal the moon to gain status and approval from his mother.
Gru (Steve Carell) is a super-villain, operating out of his suburban home that serves as a front for an underground lair where he, his partner, Dr. Nefario (Russell Brand), and thousands of short yellow minions plan their nefarious deeds.
Gru's pride is injured when an unknown super-villain steals the Great Pyramid of Giza and is described as making "all other villains look lame". Gru decides to go one better by shrinking and stealing the Earth's moon, an idea based on his childhood dreams of being an astronaut, which were always discouraged by his mother (Julie Andrews). The plan, including a spacecraft, is quite expensive, and Gru seeks a loan from the Bank of Evil. The Bank's president, Mr. Perkins (Will Arnett), is impressed by the plan but will only provide the money if Gru can obtain a shrink ray first.
Gru and his minions easily steal a shrink ray from a secret base in Asia, but the up-and-coming super-villain, Vector (Jason Segel), who was also responsible for the Pyramid theft, does the same thing. Gru fails to break into Vector's base, but notices three orphan girls, Margo (Miranda Cosgrove), Edith (Dana Gaier), and Agnes (Elsie Fisher), easily walk into the base to sell Vector cookies. Gru, faking his credentials, adopts the girls from Miss Hattie's Home for Girls, planning on using them to infiltrate Vector's base. However, Gru has much difficulty nurturing them properly between their own rambunctiousness, their ballet classes, and his own ineptitude as a parent.
Eventually, Gru and the girls successfully reacquire the shrink ray. The girls suggest a day at the local theme park to celebrate, whereupon Gru agrees, believing he can ditch the girls there. To his surprise, he comes to warm up to the girls over the course of the day, and takes them back home with him. Later, Gru returns to the Bank of Evil for his loan, but Perkins rejects him again, stating that they would rather see a younger super-villain, such as his son Vector, complete this theft. As Gru mopes about at home, the girls offer the contents of their piggy bank to fund the plan. Gru, inspired, sacrifices parts of his lair to construct the spacecraft. Gru plans to steal the moon when it is nearest the Earth, but this ends up being the same day as the girls' ballet recital. Gru becomes conflicted, and Dr. Nefario, seeing this interfering with the plan, arranges for the girls to be returned to the orphanage.
Gru proceeds with his plan to steal the moon, successfully shrinking it to fit in his hand. Gru realizes he can still make the girls' recital, but he arrives too late and finds that Vector has kidnapped them and demands the Moon as a ransom for their return. Gru makes the trade, but Vector reneges on the deal, flying off with the girls and the moon. Meanwhile, Dr Nefario has discovered that the Shrink Ray is not permanent and that an object the size of the Moon will return to normal size within hours. As the moon starts to expand in Vector's ship, Gru, Dr. Nefario, and the minions pull off a daring mid-air rescue of the girls, just as the moon explodes out from Vector's ship and launches itself back into orbit. Vector is stranded on the once-again full-sized moon.
Some time later, Gru has readopted the girls and treats them as his daughters, and he writes them a bedtime storybook framed around his own experience. Margo hugs Gru, telling him she loves him, at which he hugs her back, saying the same. The girls perform their own ballet recital for Gru, his mother, Dr. Nefario, and the minions, with the movie ending as they all get on stage to dance to "You Should Be Dancing".
