He used to work for JETT Records, was the former manager and arch-nemesis of The Chipmunks and Chipettes, and was Dave's former arch-rival and best friend. Ian attended college with Dave, his ex-roommate. When Dave first entered the headquarters, Ian wanted to be his boss since he was no longer Dave's college roommate; instead, he became his "best friend".
In the first film, Ian is visited by Dave, who presents a song that he wants produced to Ian. However, he refuses and bluntly tells Dave that he thinks it is bad and he really hated it. Then he tells Dave that since he is his friend, he recommends that Dave should quit writing music that he thinks no one will ever sing or give attention to.
Once again, Dave visits Ian to present to him Alvin, Simon, and Theodore in order to convince him that they would be JETT Records' next big hit. Unfortunately, the audition goes horribly as the nervous trio refuse to sing due to intense stage fright.
That night, in his house, Ian hears a doorbell and thinks that it is just children. However, he happens upon The Chipmunks, who sing Ian "The Chipmunk Song (Christmas Don't Be Late)" and greatly impress him and make him realize that Dave was right. He welcomes them into JETT Records and later calls Dave in the supermarket, calling him his favorite song writer and to tell him of the song's success and also informing him of the video that got 10,000,000 hits on YouTube. Later, at a Christmas concert, Ian tries to convince Dave to let him work with the trio. However, Dave quickly realizes that Ian would only exploit The Chipmunks and refuses, as well as pretending not to hear his proposition.
This angered Ian, who warns Dave not to go against him, further claiming that he never loses. He later tries to manipulate The Chipmunks by telling them that Dave is holding them back and that he could be making them 20 million dollars a day and that Dave doesn't view them in a positive light. Later at Dave's house, a misunderstanding occurs and a heartbroken group of chipmunks contact Ian to see if they can live with him. When The Chipmunks move in with Ian, life at first seems grand as they are given a plentiful amount of toys and activities, but things begin to take a turn for the worse as Ian begins to overwork and exhaust them.
Finally, at the big concert in Los Angeles, Dave wants to visits the boys, but is flatly refused by Ian. Ian further hurts their feelings by claiming that Dave sent back tickets for their concert. Later, Dave tries to sneak into The Chipmunks' performance to save them, but he is blocked by security guards. Fortunately, Claire assist Dave in his plan and manages to sneak him in by pretending that he is a journalist for a local magazine and giving him a press pass. When Dave enters the theater and calls out The Chipmunks' names, they quickly realize that Ian lied to them. In spite, they proceed to ruin the show and cause significant amounts of chaos.
Ian orders the security guards to get The Chipmunks, but they fail due to their cunning behavior, defeating the guards. Despite their efforts, Ian finally manages to once again capture Alvin, Simon, and Theodore and quickly whisks them away in a cat cage. Dave tries to stop Ian and tells him not to capture them, but Ian refuses to listen and ignores Dave as he proceeds with his plan. However, they easily escape and trick Ian with their doll doppelgangers. As Ian is chauffeured away toward the airport, he discovers the dolls and yells in defeat.
In a post-credits scene, it is revealed that The Chipmunks' escape cost Ian the world tour, as well as his career and fortune. So he tries to get three squirrels to sing, but he, of course, fails. He then breaks down and sobs.
In the second film, Ian is depicted as a shadow of his former self: Jobless and broke. It seems that he is such a poor state that he even eats a piece of muffin that had been in the garbage and a rat had gotten hold of.
Soon, Ian ends up as the adoptive father, caregiver, and manager of The Chipettes. However, he only adopted them just to get revenge on The Chipmunks.
The Chipmunks and Chipettes later meet up at West Eastman High School, but Alvin and Brittany were the only ones that ended up distrusting each other (until Alvin saves her and her sisters from Ian).
Ian tricked The Chipettes into thinking The Chipmunks were evil and that Alvin literally spit on him. Despite this, he still wanted only Brittany (whom he calls the "B-girl") as a star and didn't allow Jeanette and Eleanor on Brittany's way.
Once again, Ian loses his fortune after the girls escape just as the boys did in the first film, leaving him to lamely make up for their disappearances by dressing up as Brittany and using puppets to portray Eleanor and Jeanette. As a result, he was thrown in a dumpster by security guards.
In the third film, Ian is now working as an employee on the cruise ship, dressed like a pelican. He tries to crack The Chipmunks and The Chipettes' relationship with Dave and ruin his life.
Despite this, Ian, in a way, does re-kindle his relationship with Alvin and his brothers, along with Dave and the girls by helping Dave rescue the chipmunks.
At the end of the film, when The Chipmunks and The Chipettes perform at the International Music Awards, Dave and a now reformed Ian work together with them to keep them famous and happy, becoming best friends again. Ian sells a screenplay of Zoe's story to Hollywood, earning him his wealth, career, and fame back.
Ian Hawke:You're in my house now! Although, technically, it's not a house. It's a ship. The point is, I'll be watching you...like a hawk! - (Chipwrecked)
Ian Hawke: You know, one time in the studio, Snoop ran out of matches and got a blaze going with just two carrot sticks. I'm thinking, how hard can it be? - (Chipwrecked)
Ian Hawke: Oh, hey. I see you've found the chubby one. - (Chipwrecked)
Ian Hawke: I get it, Frenchie. You come from a rich history. Well, guess what, we're all gonna be history if we don't get out of here! - (Chipwrecked)
Ian Hawke: What? No love for Uncle Ian? - (Chipwrecked)
Ian Hawke: Seriously? Are we still talking about that? New subject: I saved Dave's life! - (Chipwrecked)
Ian Hawke: I sold Zoe's story to Hollywood. Huge bidding war. Keira Knightley is interested. I'm thinking, bid a cent from me. - (Chipwrecked)
Ian is believed to be the live-action film and human version of "Uncle" Harry.
Ian does not appear in the fourth film The Road Chip, due to David Cross’s apparent hatred of the films, but he is replaced by Agent James Suggs. He and Ian are alike in personality and appearance; both men are bald and have a personal vendetta against The Chipmunks.